Add CI with github actions

.github/workflows/test.yml

@@ -0,0 +1,14 @@
+name: "Test"
+on:
+  pull_request:
+  push:
+jobs:
+  tests:
+    strategy:
+      matrix:
+        os: [ubuntu-18.04, macos]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v2
+    - uses: cachix/install-nix-action@v8
+    - run: nix-build release.nix --arg nix '{ outPath = ./.; revCount = 123; shortRev = "abcdefgh"; }' --arg systems '[ builtins.currentSystem ]' -A build -A binaryTarball -A perlBindings -A installerScript

release.nix

@@ -348,9 +348,9 @@ let
           substitute ${./scripts/install.in} $out/install \
             ${pkgs.lib.concatMapStrings
               (system: "--replace '@binaryTarball_${system}@' $(nix --experimental-features nix-command hash-file --base16 --type sha256 ${binaryTarball.${system}}/*.tar.xz) ")
-              [ "x86_64-linux" "i686-linux" "x86_64-darwin" "aarch64-linux" ]
+              systems
             } \
-            --replace '@nixVersion@' ${build.x86_64-linux.src.version}
+            --replace '@nixVersion@' ${build.${builtins.head systems}.src.version}
 
           echo "file installer $out/install" >> $out/nix-support/hydra-build-products
         '';