Add github actions.

.github/workflows/build.yml

@@ -0,0 +1,24 @@
+name: build
+
+on: ["push", "pull_request"]
+
+jobs:
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+
+      - uses: actions/checkout@v2
+      - name: Use Node.js 16.x
+        uses: actions/setup-node@v2
+        with:
+          node-version: 16.x
+      - name: npm install, npm test
+        run: |
+          npm install
+          npm test
+      - name: Coveralls
+        uses: coverallsapp/github-action@master
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/release.yml

@@ -0,0 +1,30 @@
+name: release
+
+on:
+  release:
+    types: [created]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
+        with:
+          node-version: 16.x
+      - run: npm ci
+      - run: npm test
+
+  publish-npm:
+    needs: build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
+        with:
+          node-version: 16.x
+          registry-url: https://registry.npmjs.org/
+      - run: npm ci
+      - run: npm publish
+        env:
+          NODE_AUTH_TOKEN: ${{secrets.npm_token}}