improve CI

.github/workflows/test.yml

@@ -9,16 +9,13 @@ jobs:
         os: [ubuntu-18.04, macos-latest]
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - run: yarn install --frozen-lockfile
     - run: yarn build
-    # TODO: just commit it using github
-    - run: git diff --exit-code
-    - run: yarn test
     - name: Install Nix
       uses: ./
     - run: nix-env -iA cachix -f https://github.com/NixOS/nixpkgs/tarball/ab5863afada3c1b50fc43bf774b75ea71b287cde
     - run: cat /etc/nix/nix.conf
     # cachix should be available and be able to configure a cache
     - run: cachix use cachix
-    - run: nix-build test.nix
+    - run: nix-build test.nix