Use github actions

Closes #115

.github/workflows/format.yml

@@ -0,0 +1,28 @@
+name: Format
+on:
+  push:
+    branches:
+      - master
+jobs:
+  build:
+    name: Format OCaml code
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - uses: avsm/[email protected]
+        with:
+          ocaml-version: 4.09.0
+      - name: Install dependencies
+        run: opam install dune ocamlformat
+      - name: Build
+        run: opam exec -- dune build
+      - name: Format
+        run: opam exec -- dune build @fmt --auto-promote || true
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v1
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          commit-message: ocamlformat fixes
+          title: ocamlformat fixes
+          body: This is an auto-generated PR with fixes by ocamlformat.
+          labels: ocamlformat, automated pr

.github/workflows/test.yml

@@ -0,0 +1,27 @@
+name: RoutesTest
+on:
+  pull_request:
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        ocaml-version: [ '4.09.0', '4.08.1', '4.07.1', '4.06.1', '4.05.0', '4.04.1' ]
+    steps:
+      - uses: actions/checkout@master
+      - uses: avsm/[email protected]
+        with:
+          ocaml-version: ${{ matrix.ocaml-version }}
+      - name: Install dependencies
+        run: |
+          opam pin add opium_kernel.dev -n .
+          opam pin add opium.dev -n
+          opam depext -yt opium_kernel
+          opam depext -yt opium
+          opam install -t . --deps-only
+      - name: Build
+        run: opam exec -- dune build
+      - name: Run tests
+        run: opam exec -- dune runtest