Configure github actions for CI

.github/continuous_integration.yml

@@ -0,0 +1,29 @@
+name: CI
+
+on: [push, pull_request]
+
+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:
+        cache: 'npm'
+        node-version: ${{ matrix.node-version }}
+
+    - name: Update npm
+      run: npm i -g npm@7
+
+    - name: Install node modules
+      run: npm ci
+
+    - name: Run tests
+      run: npm test