Replace Travis with GitHub Actions (#496)

* Add github actions

* fix: Add yarn to shell.nix

* fix: Make test work again

* Rename job

* Use frozen yarn lockfile and yarn cache

* Separate, re-order steps

* Only test node 12.x

* fix: standalone build

* chore: Upgrade netlify node/yarn versions

* chore: Bundle yarn

* Remove .travis.yml

Author: jstcki

.github/workflows/test.yml

@@ -0,0 +1,38 @@
+name: Node CI
+
+on: [push]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [12.x]
+
+    steps:
+      - uses: actions/checkout@v1
+
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node-version }}
+
+      - name: Get yarn cache
+        id: yarn-cache
+        run: echo "::set-output name=dir::$(yarn cache dir)"
+
+      - uses: actions/cache@v1
+        with:
+          path: ${{ steps.yarn-cache.outputs.dir }}
+          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-yarn-
+
+      - name: Install dependencies
+        run: yarn --frozen-lockfile
+
+      - name: Run test
+        run: yarn test
+        env:
+          CI: true