Use github actions

.github/workflows/build.yaml.txt

@@ -0,0 +1,33 @@
+name: Build site
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - '.github/workflows/build.yml'
+      - 'README.md'
+
+jobs:
+  build_site:
+    runs-on: ubuntu-latest
+    name: Build site
+    steps:
+      - uses: actions/checkout@master
+        with:
+          fetch-depth: 1
+      - uses: actions/setup-node@master
+        with:
+          node-version: '12.x'
+      - name: Determine npm cache directory
+        id: npm-cache
+        run: |
+          echo "::set-output name=dir::$(npm config get cache)"
+      - name: Restore npm cache
+        uses: actions/cache@v1
+        with:
+          path: ${{ steps.npm-cache.outputs.dir }}
+          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-
+      - run: npm run build