Create dockerimage.yml

.github/workflows/dockerimage.yml

+name: Docker Image CI
+
+on: [push]
+
+jobs:
+
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Build the Docker image
+      run: docker build . --file docker/Dockerfile --tag sgxcontainer:$(date +%s)