Replace Travis with GitHub Actions

Author: danbovey

.github/workflows/test.yml

@@ -0,0 +1,23 @@
+name: Test
+
+on:
+  pull_request:
+    branches: [master]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Cache node modules
+        id: cache
+        uses: actions/cache@v2
+        with:
+          path: node_modules
+          key: cache-node-modules-${{ hashFiles('package-lock.json') }}
+      - name: npm install
+        if: steps.cache.outputs.cache-hit != 'true'
+        run: npm ci
+      - run: npm run lint
+      - run: npm run test
+      - run: npm run build