Print the image name that's being built

[ahmetb]

Skaffold 0.7.0

I've reported this before, my general feeling while using skaffold is that a lot of things are going on (like many docker builds but I can't clearly tell what's building.

Take the sample output below. It's super difficult to tell two separate images being built and which one is failing (which artifact was the build for).

Please consider adding commands executed to logs, or add some separator between artifact builds indicating artifact name.

Step 10/11 : EXPOSE 3550
 ---> Running in 150ccdcf6a23
 ---> 5765c376ffc3
Step 11/11 : ENTRYPOINT /productcatalogservice
 ---> Running in 35947c7bc94b
 ---> 21ed0677bc68
Successfully built 21ed0677bc68
Successfully tagged d4f59d740fd86db565360b79c61cd951:latest
Successfully tagged productcatalogservice:20c2dd3-dirty-e3e8e3fa36ecd0da
Sending build context to Docker daemon  2.048kB
Step 1/7 : FROM grpc/python:1.0
 ---> b1058820060c
Step 2/7 : ENV PYTHONUNBUFFERED=0
 ---> Using cache
 ---> 761b67a669a2
Step 3/7 : ADD ./*.py /home/
FATA[0071] first build: exiting dev mode because the first build failed: running build for artifact: running build: ADD failed: no source files were specified