Update rubocop requirement to >= 0.54, < 0.59

Updates the requirements on [rubocop](https://github.com/rubocop-hq/rubocop) to permit the latest version.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop@v0.54.0...v0.58.1)

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -2,17 +2,18 @@ PATH
   remote: .
   specs:
     ramsey_cop (0.9.0)
-      rubocop (~> 0.54.0)
+      rubocop (>= 0.54, < 0.59)
 
 GEM
   remote: https://rubygems.org/
   specs:
     ast (2.4.0)
     diff-lcs (1.3)
+    jaro_winkler (1.5.1)
     parallel (1.12.1)
-    parser (2.5.1.0)
+    parser (2.5.1.2)
       ast (~> 2.4.0)
-    powerpack (0.1.1)
+    powerpack (0.1.2)
     rainbow (3.0.0)
     rake (12.3.1)
     rspec (3.7.0)
@@ -28,15 +29,16 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.7.0)
     rspec-support (3.7.1)
-    rubocop (0.54.0)
+    rubocop (0.58.1)
+      jaro_winkler (~> 1.5.1)
       parallel (~> 1.10)
-      parser (>= 2.5)
+      parser (>= 2.5, != 2.5.1.1)
       powerpack (~> 0.1)
       rainbow (>= 2.2.2, < 4.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (~> 1.0, >= 1.0.1)
     ruby-progressbar (1.9.0)
-    unicode-display_width (1.3.2)
+    unicode-display_width (1.4.0)
 
 PLATFORMS
   ruby

ramsey_cop.gemspec

@@ -19,7 +19,7 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(/^exe\//) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  spec.add_dependency "rubocop", "~> 0.54.0"
+  spec.add_dependency "rubocop", ">= 0.54", "< 0.59"
   spec.add_development_dependency "bundler", "~> 1.14"
   spec.add_development_dependency "rake", "~> 12.3"
   spec.add_development_dependency "rspec", "~> 3.0"