add github actions

Author: reliveyy

.github/workflows/ci.yml

@@ -0,0 +1,21 @@
+name: ci
+
+on:
+  push:
+    branches: pi
+
+jobs:
+  main:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      - name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - name: Build and push
+        run: tools/build utils and tools/push utils