add github actions (#247)

.github/workflows/ci.yml

@@ -0,0 +1,39 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  npm_test:
+    name: npm test
+
+    strategy:
+      matrix:
+        include:
+          - node: 16.x
+
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js ${{ matrix.node }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node }}
+
+      - name: Restore npm cache
+        uses: actions/cache@v2
+        with:
+          path: ~/.npm
+          key: ${{ runner.os }}-${{ matrix.node }}-node-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-${{ matrix.node }}-node-
+
+      - name: npm install and test
+        run: |
+          npm install
+          npm test