Remove travis. Add GA for tests. (#83)

.github/workflows/tests.yml

@@ -0,0 +1,27 @@
+name: Tests
+
+on:
+  pull_request:
+
+jobs:
+  build:
+   runs-on: ubuntu-latest
+
+   steps:
+    # See: https://help.github.com/en/actions/automating-your-workflow-with-github-actions/configuring-a-workflow#using-the-checkout-action
+    - uses: actions/checkout@v2
+
+    - name: Use Node.js 14
+      uses: actions/setup-node@v1
+      with:
+        node-version: '14.x'
+
+    - name: Cache dependencies
+      uses: actions/cache@v1
+      with:
+        path: ~/.npm
+        key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
+        restore-keys: |
+          ${{ runner.os }}-node-
+    - run: npm ci
+    - run: npm test