Build: Switch CI to GitHub Actions

Closes gh-110.

Author: mgol

.github/workflows/node.js.yml

@@ -0,0 +1,35 @@
+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        NODE_VERSION: [16.x]
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+
+    - name: Cache
+      uses: actions/cache@v2
+      with:
+        path: ~/.npm
+        key: ${{ runner.os }}-node-${{ matrix.NODE_VERSION }}-npm-lock-${{ hashFiles('**/package-lock.json') }}
+        restore-keys: |
+          ${{ runner.os }}-node-${{ matrix.NODE_VERSION }}-npm-lock-
+
+    - name: Use Node.js ${{ matrix.NODE_VERSION }}
+      uses: actions/setup-node@v2.1.2
+      with:
+        node-version: ${{ matrix.NODE_VERSION }}
+
+    - name: Install dependencies
+      run: |
+        npm install
+
+    - name: Run tests
+      run: |
+        npm test