Set up CI using a GitHub actions (#21)

Author: koddsson

.github/workflows/nodejs.yml

@@ -0,0 +1,44 @@
+name: Build
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Get sources
+        uses: actions/checkout@v1
+
+      - name: Restore npm cache
+        uses: actions/cache@v2
+        with:
+          path: ~/.npm
+          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-
+      - uses: actions/cache@v2
+        with:
+          path: node_modules
+          key: ${{ runner.os }}-node-modules-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-modules-
+      - name: Use Node.js 12
+        uses: actions/setup-node@v2
+        with:
+          node-version: '12'
+
+      - name: Install dependencies
+        run: npm install
+
+      - name: Build
+        run: npm run build --if-present
+
+      - name: Test
+        run: npm run test
+        env:
+          CI: true