Run tests in GitHub actions

.github/workflows/test.yml

@@ -0,0 +1,35 @@
+# This is a basic workflow to help you get started with Actions
+
+name: CI
+
+on: [push, pull_request]
+
+# A workflow run is made up of one or more jobs that can run sequentially or in parallel
+jobs:
+  test:
+    # The type of runner that the job will run on
+    runs-on: ubuntu-latest
+
+    # Steps represent a sequence of tasks that will be executed as part of the job
+    steps:
+    # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
+    - uses: actions/checkout@v2
+
+    - name: Setup Node.js environment
+      uses: actions/setup-node@v1
+      with:
+        node-version: 12.x
+
+    - name: Cache node_modules
+      id: cache-node_modules
+      uses: actions/cache@v2
+      with:
+        path: node_modules
+        key: node_modules-ubuntu-${{ hashFiles('yarn.lock') }}
+
+    - name: yarn
+      if: steps.cache-node_modules.outputs.cache-hit != 'true'
+      run: yarn
+
+    - name: Run tests
+      run: npm test