Add github workflow (#148)

.github/workflows/haskell.yml

@@ -0,0 +1,50 @@
+name: Haskell CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      matrix:
+        ghc: ['8.6.5', '8.8.3']
+        cabal: ['2.4.1.0', '3.0.0.0']
+        os: [ubuntu-latest, macOS-latest] #, windows-latest]
+        exclude:
+          # GHC 8.8+ only works with cabal v3+
+          - ghc: 8.8.3
+            cabal: 2.4.1.0
+
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-haskell@v1.1
+      with:
+        ghc-version: ${{ matrix.ghc }}
+        cabal-version: ${{ matrix.cabal }}
+
+    - name: Cache
+      uses: actions/cache@v1
+      env:
+        cache-name: cache-cabal
+      with:
+        path: ~/.cabal
+        key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/*.cabal') }}-${{ hashFiles('**/cabal.project') }}
+        restore-keys: |
+          ${{ runner.os }}-build-${{ env.cache-name }}-
+          ${{ runner.os }}-build-
+          ${{ runner.os }}-
+
+    - name: Install dependencies
+      run: |
+        cabal v2-update
+        cabal v2-build --only-dependencies --enable-tests --enable-benchmarks
+    - name: Build
+      run: cabal v2-build --enable-tests --enable-benchmarks all
+    - name: Run tests
+      run: cabal v2-test all

.travis.yml

@@ -18,7 +18,7 @@ matrix:
   # Cabal
   - ghc: 8.4.4
   - ghc: 8.6.5
-  - ghc: 8.8.2
+  - ghc: 8.8.3
 
   # Stack
   - ghc: 8.6.5

stack.yaml.lock

@@ -0,0 +1,12 @@
+# This file was autogenerated by Stack.
+# You should not edit this file by hand.
+# For more information, please see the documentation at:
+#   https://docs.haskellstack.org/en/stable/lock_files
+
+packages: []
+snapshots:
+- completed:
+    size: 524127
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/14/6.yaml
+    sha256: dc70dfb45e2c32f54719819bd055f46855dd4b3bd2e58b9f3f38729a2d553fbb
+  original: lts-14.6