create GH Actions workflow

.github/workflows/tests.yml

@@ -0,0 +1,18 @@
+name: aws-lambda-power-tuning-tests
+run-name: ${{ github.actor }} is running integration tests
+on: [push, pull_request]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [12.x, 13.x, 14.x, 15.x, 16.x]
+    steps:
+      - uses: actions/checkout@v3
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+      - run: npm ci
+      - run: npm test
+      - run: npm run coverage && cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js && rm -rf ./coverage