chore: build docker test image

.github/workflows/build-dockerfile.yml

@@ -0,0 +1,34 @@
+name: Build
+
+on:
+  push:
+    branches:
+      - master
+      - release
+      - beta
+      - tnordquist/test-ci
+    paths:
+      - ./docker
+      - .github
+
+jobs:
+  create-image:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: ./Dockerfile
+          push: true
+          tags: thomasnordquist/mqtt-explorer-ui-tests:latest