CI: added github actions

Author: f3l1x

.github/workflows/docker.yml

@@ -0,0 +1,54 @@
+name: Docker
+
+on:
+  push:
+    branches: master
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+          - version: "10"
+          - version: "11"
+          - version: "12"
+          - version: "13"
+
+      fail-fast: false
+
+    name: Docker (dockette/postgres:${{ matrix.version }})
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Cache Docker layers
+        uses: actions/cache@v2
+        with:
+          path: /tmp/.buildx-cache
+          key: ${{ runner.os }}-buildx-${{ github.sha }}-${{ matrix.version }}
+          restore-keys: |
+            ${{ runner.os }}-buildx-${{ github.sha }}-${{ matrix.version }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          file: ${{ matrix.version  }}/Dockerfile
+          push: true
+          tags: dockette/postgres:${{ matrix.version }}
+          cache-from: type=local,src=/tmp/.buildx-cache
+          cache-to: type=local,dest=/tmp/.buildx-cache
+          platforms: linux/amd64,linux/arm64