Add tests to pipeline

Author: webbertakken

.github/workflows/main.yml

@@ -4,6 +4,20 @@ on:
   push: { branches: [master] }
 
 jobs:
+  tests:
+    name: Tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 12.x
+      - run: yarn
+      - run: yarn lint
+      - run: yarn test
+      - run: yarn build || { echo "build command should always succeed" ; exit 61; }
+      - run: yarn build --quiet && git diff --quiet action || { echo "action should be auto generated" ; exit 62; }
+
   requestManualActivationFile:
     name: Request manual activation file 🔑
     runs-on: ubuntu-latest