add integration test container build to weekly tests

Signed-off-by: Shyam Jesalpura s.jesalpura@gmail.com

.github/workflows/build_function_images.yml → .github/workflows/build_docker_images.yml

@@ -1,4 +1,4 @@
-name: Check if the docker images of the functions build successfully
+name: Check if the docker images build successfully
 
 on: 
   workflow_dispatch:
@@ -7,7 +7,7 @@ on:
 
 
 jobs:
-  build_images:
+  function_images:
     name: Build function docker images
     runs-on: ubuntu-18.04
     strategy:
@@ -26,4 +26,14 @@ jobs:
       # https://git.luolix.topmunity/t/attempting-to-build-docker-image-with-copy-from-on-actions/16715
       # https://stackoverflow.com/questions/51115856/docker-failed-to-export-image-failed-to-create-image-failed-to-get-layer
       run: |
-        DOCKER_BUILDKIT=1 docker build ./function-images/${{ matrix.image }}
+        DOCKER_BUILDKIT=1 docker build ./function-images/${{ matrix.image }}
+  integ_test_image:
+    name: Build integration test docker images
+    runs-on: ubuntu-18.04
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        ref: master
+    - name: docker build images
+      run: |
+        DOCKER_BUILDKIT=1 docker build --file ./scripts/Dockerfile.integration_test .