Github Actions in CI to check both ghc-8.6.5 and ghc-8.10.2 builds

.github/workflows/haskell.yml

@@ -0,0 +1,60 @@
+name: Haskell CI
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+
+    defaults:
+      run:
+        shell: bash
+
+    strategy:
+      fail-fast: false
+      matrix:
+        ghc: ["8.6.5", "8.10.2"]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+      exclude:
+        - os: macos-latest
+          ghc: 8.6.5
+
+    steps:
+    - uses: actions/checkout@v1
+
+    - name: Select build directory
+      run: echo "CABAL_BUILDDIR=dist" >> $GITHUB_ENV
+
+    - uses: actions/setup-haskell@v1
+      id: setup-haskell
+      with:
+        ghc-version: ${{ matrix.ghc }}
+        cabal-version: '3.2.0.0'
+
+    - name: Cabal update
+      run: cabal update
+
+    - name: Cabal Configure
+      run: cabal configure --builddir="$CABAL_BUILDDIR" --enable-tests --enable-benchmarks --write-ghc-environment-files=always
+
+    - uses: actions/cache@v2
+      if: matrix.os != 'macos-latest'
+      name: Cache cabal store
+      with:
+        path: |
+          ${{ steps.setup-haskell.outputs.cabal-store }}
+          dist
+        key: cache-${{ runner.os }}-${{ matrix.ghc }}-v1-${{ hashFiles('cabal-cache.cabal') }}-${{ github.sha }}
+        restore-keys: cache-${{ runner.os }}-${{ matrix.ghc }}-v1-${{ hashFiles('cabal-cache.cabal') }}-
+
+    - name: Install dependencies
+      run: cabal build all --builddir="$CABAL_BUILDDIR" --only-dependencies
+
+    - name: Build
+      run: cabal build all --builddir="$CABAL_BUILDDIR"
+
+    - name: Git clone
+      run: git clone https://github.com/input-output-hk/cardano-mainnet-mirror
+
+    - name: Run tests
+      run: cabal test all --builddir="$CABAL_BUILDDIR"