Test cachix action

.github/workflows/test.yml

@@ -0,0 +1,21 @@
+name: "Test"
+on:
+  pull_request:
+  push:
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2.4.0
+      - uses: cachix/install-nix-action@v16
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
+          extra_nix_config: |
+            experimental-features = nix-command flakes
+      - uses: cachix/cachix-action@v10
+        with:
+          name: alejandro-dotfiles
+          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+      - run: nix-env -i nixos-rebuild -f '<nixpkgs>'
+      - run: nixos-rebuild build --flake .#gospel
+      - run: echo OK