update added testing action

.github/workflows/testing.yml

@@ -0,0 +1,26 @@
+name: testing
+
+on:
+  push:
+    branches: [master]
+
+jobs:
+  testing:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - name: Setup Node
+        uses: actions/setup-node@v1
+        with:
+          node-version: 13
+          registry-url: https://registry.npmjs.org/
+      - name: Install
+        run: npm install
+      - name: Build
+        run: npm run build
+      - name: Run jest tests
+        run: npm test
+      - uses: codecov/codecov-action@v1
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }} #
+