Create docker-image.yml

.github/workflows/docker-image.yml

+name: Docker Image CI
+
+on:
+  push:
+    branches: [ develop ]
+  pull_request:
+    branches: [ develop ]
+
+jobs:
+
+  build:
+
+    runs-on: [self-hosted, Linux]
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build the Docker image
+      run: docker build . --file Dockerfile --tag democi:$(date +%s)