Add daily npm install and test workflow (#31)

* Add daily unit test workflow

.github/workflows/daily.yml

@@ -0,0 +1,34 @@
+name: Daily - Do npm install and run all unit tests
+
+on:
+  schedule:
+    # run daily at midnight
+    - cron: '0 0 * * *'
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        node: [14]
+        os: [ubuntu-latest]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm i --package-lock --package-lock-only
+    - run: npm ci
+    - name: run unit tests
+      run: npm run test
+    - name: Slack Notification
+      if: ${{ failure() }}
+      uses: rtCamp/action-slack-notify@v2
+      env:
+        SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK }}
+        SLACK_TITLE: 'Node version'
+        SLACK_MESSAGE: ${{ matrix.node }}
+        SLACK_COLOR: ${{ job.status == 'success' && 'good' || job.status == 'cancelled' && '#808080' || 'danger' }}
+