Issue salesforce#213 -- added gh-actions flow for building and testin…

…g tough-cookie with all current version of node. This should replace our Travis testing.

.github/workflows/integration.yaml

@@ -0,0 +1,26 @@
+name: Actions-CI 
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [12.x, 14.x, 16.x]
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v2
+        with:
+          node-version: ${{ matrix.node-version }}
+      - name: Install dependencies and test
+        run: npm ci
+      - run: npm test