diff --git a/.credo.exs b/.credo.exs
new file mode 100644
index 0000000..7bc729a
--- /dev/null
+++ b/.credo.exs
@@ -0,0 +1,189 @@
+# This file contains the configuration for Credo and you are probably reading
+# this after creating it with `mix credo.gen.config`.
+#
+# If you find anything wrong or unclear in this file, please report an
+# issue on GitHub: https://github.com/rrrene/credo/issues
+#
+%{
+  #
+  # You can have as many configs as you like in the `configs:` field.
+  configs: [
+    %{
+      #
+      # Run any config using `mix credo -C <name>`. If no config name is given
+      # "default" is used.
+      #
+      name: "default",
+      #
+      # These are the files included in the analysis:
+      files: %{
+        #
+        # You can give explicit globs or simply directories.
+        # In the latter case `**/*.{ex,exs}` will be used.
+        #
+        included: [
+          "lib/",
+          "src/",
+          "test/",
+          "web/",
+          "apps/*/lib/",
+          "apps/*/src/",
+          "apps/*/test/",
+          "apps/*/web/"
+        ],
+        excluded: [~r"/_build/", ~r"/deps/", ~r"/node_modules/"]
+      },
+      #
+      # Load and configure plugins here:
+      #
+      plugins: [],
+      #
+      # If you create your own checks, you must specify the source files for
+      # them here, so they can be loaded by Credo before running the analysis.
+      #
+      requires: [],
+      #
+      # If you want to enforce a style guide and need a more traditional linting
+      # experience, you can change `strict` to `true` below:
+      #
+      strict: false,
+      #
+      # To modify the timeout for parsing files, change this value:
+      #
+      parse_timeout: 5000,
+      #
+      # If you want to use uncolored output by default, you can change `color`
+      # to `false` below:
+      #
+      color: true,
+      #
+      # You can customize the parameters of any check by adding a second element
+      # to the tuple.
+      #
+      # To disable a check put `false` as second element:
+      #
+      #     {Credo.Check.Design.DuplicatedCode, false}
+      #
+      checks: [
+        #
+        ## Consistency Checks
+        #
+        {Credo.Check.Consistency.ExceptionNames, []},
+        {Credo.Check.Consistency.LineEndings, []},
+        {Credo.Check.Consistency.ParameterPatternMatching, []},
+        {Credo.Check.Consistency.SpaceAroundOperators, []},
+        {Credo.Check.Consistency.SpaceInParentheses, []},
+        {Credo.Check.Consistency.TabsOrSpaces, []},
+
+        #
+        ## Design Checks
+        #
+        # You can customize the priority of any check
+        # Priority values are: `low, normal, high, higher`
+        #
+        {Credo.Check.Design.AliasUsage,
+         [priority: :low, if_nested_deeper_than: 2, if_called_more_often_than: 0]},
+        # You can also customize the exit_status of each check.
+        # If you don't want TODO comments to cause `mix credo` to fail, just
+        # set this value to 0 (zero).
+        #
+        {Credo.Check.Design.TagTODO, [exit_status: 2]},
+        {Credo.Check.Design.TagFIXME, []},
+
+        #
+        ## Readability Checks
+        #
+        {Credo.Check.Readability.AliasOrder, []},
+        {Credo.Check.Readability.FunctionNames, []},
+        {Credo.Check.Readability.LargeNumbers, []},
+        {Credo.Check.Readability.MaxLineLength, [priority: :low, max_length: 120]},
+        {Credo.Check.Readability.ModuleAttributeNames, []},
+        {Credo.Check.Readability.ModuleDoc, []},
+        {Credo.Check.Readability.ModuleNames, []},
+        {Credo.Check.Readability.ParenthesesInCondition, []},
+        {Credo.Check.Readability.ParenthesesOnZeroArityDefs, []},
+        {Credo.Check.Readability.PredicateFunctionNames, []},
+        {Credo.Check.Readability.PreferImplicitTry, []},
+        {Credo.Check.Readability.RedundantBlankLines, []},
+        {Credo.Check.Readability.Semicolons, []},
+        {Credo.Check.Readability.SpaceAfterCommas, []},
+        {Credo.Check.Readability.StringSigils, []},
+        {Credo.Check.Readability.TrailingBlankLine, []},
+        {Credo.Check.Readability.TrailingWhiteSpace, []},
+        {Credo.Check.Readability.UnnecessaryAliasExpansion, []},
+        {Credo.Check.Readability.VariableNames, []},
+
+        #
+        ## Refactoring Opportunities
+        #
+        {Credo.Check.Refactor.CondStatements, []},
+        {Credo.Check.Refactor.CyclomaticComplexity, []},
+        {Credo.Check.Refactor.FunctionArity, []},
+        {Credo.Check.Refactor.LongQuoteBlocks, []},
+        # {Credo.Check.Refactor.MapInto, []},
+        {Credo.Check.Refactor.MatchInCondition, []},
+        {Credo.Check.Refactor.NegatedConditionsInUnless, []},
+        {Credo.Check.Refactor.NegatedConditionsWithElse, []},
+        {Credo.Check.Refactor.Nesting, []},
+        {Credo.Check.Refactor.UnlessWithElse, []},
+        {Credo.Check.Refactor.WithClauses, []},
+
+        #
+        ## Warnings
+        #
+        {Credo.Check.Warning.ApplicationConfigInModuleAttribute, []},
+        {Credo.Check.Warning.BoolOperationOnSameValues, []},
+        {Credo.Check.Warning.ExpensiveEmptyEnumCheck, []},
+        {Credo.Check.Warning.IExPry, []},
+        {Credo.Check.Warning.IoInspect, []},
+        # {Credo.Check.Warning.LazyLogging, []},
+        {Credo.Check.Warning.MixEnv, false},
+        {Credo.Check.Warning.OperationOnSameValues, []},
+        {Credo.Check.Warning.OperationWithConstantResult, []},
+        {Credo.Check.Warning.RaiseInsideRescue, []},
+        {Credo.Check.Warning.UnusedEnumOperation, []},
+        {Credo.Check.Warning.UnusedFileOperation, []},
+        {Credo.Check.Warning.UnusedKeywordOperation, []},
+        {Credo.Check.Warning.UnusedListOperation, []},
+        {Credo.Check.Warning.UnusedPathOperation, []},
+        {Credo.Check.Warning.UnusedRegexOperation, []},
+        {Credo.Check.Warning.UnusedStringOperation, []},
+        {Credo.Check.Warning.UnusedTupleOperation, []},
+        {Credo.Check.Warning.UnsafeExec, []},
+
+        #
+        # Checks scheduled for next check update (opt-in for now, just replace `false` with `[]`)
+
+        #
+        # Controversial and experimental checks (opt-in, just replace `false` with `[]`)
+        #
+        {Credo.Check.Consistency.MultiAliasImportRequireUse, false},
+        {Credo.Check.Consistency.UnusedVariableNames, false},
+        {Credo.Check.Design.DuplicatedCode, false},
+        {Credo.Check.Readability.AliasAs, false},
+        {Credo.Check.Readability.BlockPipe, false},
+        {Credo.Check.Readability.ImplTrue, false},
+        {Credo.Check.Readability.MultiAlias, false},
+        {Credo.Check.Readability.SeparateAliasRequire, false},
+        {Credo.Check.Readability.SinglePipe, false},
+        {Credo.Check.Readability.Specs, false},
+        {Credo.Check.Readability.StrictModuleLayout, false},
+        {Credo.Check.Readability.WithCustomTaggedTuple, false},
+        {Credo.Check.Refactor.ABCSize, false},
+        {Credo.Check.Refactor.AppendSingleItem, false},
+        {Credo.Check.Refactor.DoubleBooleanNegation, false},
+        {Credo.Check.Refactor.ModuleDependencies, false},
+        {Credo.Check.Refactor.NegatedIsNil, false},
+        {Credo.Check.Refactor.PipeChainStart, false},
+        {Credo.Check.Refactor.VariableRebinding, false},
+        {Credo.Check.Warning.LeakyEnvironment, false},
+        {Credo.Check.Warning.MapGetUnsafePass, false},
+        {Credo.Check.Warning.UnsafeToAtom, false}
+
+        #
+        # Custom checks can be created using `mix credo.gen.check`.
+        #
+      ]
+    }
+  ]
+}
diff --git a/mix.exs b/mix.exs
index 6d3c1bc..5425a4d 100644
--- a/mix.exs
+++ b/mix.exs
@@ -7,7 +7,13 @@ defmodule Nilsimsa.MixProject do
       version: "0.1.0",
       elixir: "~> 1.11",
       start_permanent: Mix.env() == :prod,
-      deps: deps()
+      deps: deps(),
+      preferred_cli_env: [
+        coveralls: :test,
+        "coveralls.detail": :test,
+        "coveralls.html": :test
+      ],
+      test_coverage: [tool: ExCoveralls]
     ]
   end
 
@@ -21,8 +27,9 @@ defmodule Nilsimsa.MixProject do
   # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
-      # {:dep_from_hexpm, "~> 0.3.0"},
-      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
+      {:credo, "~> 1.5", only: [:dev, :test], runtime: false},
+      {:dialyxir, "~> 1.1", only: [:dev], runtime: false},
+      {:excoveralls, "~> 0.10", only: :test, runtime: false}
     ]
   end
 end
diff --git a/mix.lock b/mix.lock
new file mode 100644
index 0000000..4c0f16d
--- /dev/null
+++ b/mix.lock
@@ -0,0 +1,17 @@
+%{
+  "bunt": {:hex, :bunt, "0.2.0", "951c6e801e8b1d2cbe58ebbd3e616a869061ddadcc4863d0a2182541acae9a38", [:mix], [], "hexpm", "7af5c7e09fe1d40f76c8e4f9dd2be7cebd83909f31fee7cd0e9eadc567da8353"},
+  "certifi": {:hex, :certifi, "2.6.1", "dbab8e5e155a0763eea978c913ca280a6b544bfa115633fa20249c3d396d9493", [:rebar3], [], "hexpm", "524c97b4991b3849dd5c17a631223896272c6b0af446778ba4675a1dff53bb7e"},
+  "credo": {:hex, :credo, "1.5.6", "e04cc0fdc236fefbb578e0c04bd01a471081616e741d386909e527ac146016c6", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2.8", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "4b52a3e558bd64e30de62a648518a5ea2b6e3e5d2b164ef5296244753fc7eb17"},
+  "dialyxir": {:hex, :dialyxir, "1.1.0", "c5aab0d6e71e5522e77beff7ba9e08f8e02bad90dfbeffae60eaf0cb47e29488", [:mix], [{:erlex, ">= 0.2.6", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "07ea8e49c45f15264ebe6d5b93799d4dd56a44036cf42d0ad9c960bc266c0b9a"},
+  "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
+  "excoveralls": {:hex, :excoveralls, "0.14.1", "14140e4ef343f2af2de33d35268c77bc7983d7824cb945e6c2af54235bc2e61f", [:mix], [{:hackney, "~> 1.16", [hex: :hackney, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "4a588f9f8cf9dc140cc1f3d0ea4d849b2f76d5d8bee66b73c304bb3d3689c8b0"},
+  "file_system": {:hex, :file_system, "0.2.10", "fb082005a9cd1711c05b5248710f8826b02d7d1784e7c3451f9c1231d4fc162d", [:mix], [], "hexpm", "41195edbfb562a593726eda3b3e8b103a309b733ad25f3d642ba49696bf715dc"},
+  "hackney": {:hex, :hackney, "1.17.4", "99da4674592504d3fb0cfef0db84c3ba02b4508bae2dff8c0108baa0d6e0977c", [:rebar3], [{:certifi, "~>2.6.1", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "~>6.1.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "~>1.0.0", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~>1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:parse_trans, "3.3.1", [hex: :parse_trans, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "~>1.1.0", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}, {:unicode_util_compat, "~>0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "de16ff4996556c8548d512f4dbe22dd58a587bf3332e7fd362430a7ef3986b16"},
+  "idna": {:hex, :idna, "6.1.1", "8a63070e9f7d0c62eb9d9fcb360a7de382448200fbbd1b106cc96d3d8099df8d", [:rebar3], [{:unicode_util_compat, "~>0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "92376eb7894412ed19ac475e4a86f7b413c1b9fbb5bd16dccd57934157944cea"},
+  "jason": {:hex, :jason, "1.2.2", "ba43e3f2709fd1aa1dce90aaabfd039d000469c05c56f0b8e31978e03fa39052", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "18a228f5f0058ee183f29f9eae0805c6e59d61c3b006760668d8d18ff0d12179"},
+  "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], [], "hexpm", "69b09adddc4f74a40716ae54d140f93beb0fb8978d8636eaded0c31b6f099f16"},
+  "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm", "f278585650aa581986264638ebf698f8bb19df297f66ad91b18910dfc6e19323"},
+  "parse_trans": {:hex, :parse_trans, "3.3.1", "16328ab840cc09919bd10dab29e431da3af9e9e7e7e6f0089dd5a2d2820011d8", [:rebar3], [], "hexpm", "07cd9577885f56362d414e8c4c4e6bdf10d43a8767abb92d24cbe8b24c54888b"},
+  "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.6", "cf344f5692c82d2cd7554f5ec8fd961548d4fd09e7d22f5b62482e5aeaebd4b0", [:make, :mix, :rebar3], [], "hexpm", "bdb0d2471f453c88ff3908e7686f86f9be327d065cc1ec16fa4540197ea04680"},
+  "unicode_util_compat": {:hex, :unicode_util_compat, "0.7.0", "bc84380c9ab48177092f43ac89e4dfa2c6d62b40b8bd132b1059ecc7232f9a78", [:rebar3], [], "hexpm", "25eee6d67df61960cf6a794239566599b09e17e668d3700247bc498638152521"},
+}