Create GitHub workflow

.github/workflows/main.yml

@@ -0,0 +1,32 @@
+name: buildx
+
+on:
+  pull_request:
+    branches: master
+  push:
+    branches: master
+    tags:
+
+jobs:
+  buildx:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v1
+      -
+        name: Set up Docker Buildx
+        id: buildx
+        uses: crazy-max/ghaction-docker-buildx@v1
+        with:
+          version: v1.1.0
+      -
+        name: Print builder available platforms
+        run: echo ${{ steps.buildx.outputs.platforms }}
+      -
+        name: Run Buildx
+        run: |
+          docker buildx build \
+            --platform \linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64 \
+            --output "type=image,push=false" \
+            --file Dockerfile