ci: switch Travis to Github Actions

.github/workflows/continuous-integration.yaml

@@ -0,0 +1,36 @@
+name: Continuous Integration
+
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [10, 12, 14]
+        mongodb-version: [4.4] # the latest stable version
+
+    steps:
+    - name: Git checkout
+      uses: actions/checkout@v2
+
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+
+    - name: Start MongoDB
+      uses: supercharge/[email protected]
+      with:
+        mongodb-version: ${{ matrix.mongodb-version }}
+
+    - run: npm install
+    - run: npm test
+      env:
+        CI: true