Attach docker repo-container cleanup to docker/build.done task
Attach docker repo-container cleanup to docker/build.done task

The artifacts task was not being used in the
dependency chain, so it was not being called.

Cleanup is now in docker/build.done.

Change-Id: I67106496ea2a786ee17bef9fb2e6238b6d22c9cc
Closes-Bug: #1461502

teselkin/fuel-main,teselkin/fuel-main,teselkin/fuel-main,SergK/fuel-main,SergK/fuel-main,eayunstack/fuel-main,stackforge/fuel-main,SmartInfrastructures/fuel-main-dev,huntxu/fuel-main,AnselZhangGit/fuel-main,SmartInfrastructures/fuel-main-dev,huntxu/fuel-main,eayunstack/fuel-main,AnselZhangGit/fuel-main,AnselZhangGit/fuel-main,SmartInfrastructures/fuel-main-dev,AnselZhangGit/fuel-main,SmartInfrastructures/fuel-main-dev,huntxu/fuel-main,stackforge/fuel-main,teselkin/fuel-main,stackforge/fuel-main,SergK/fuel-main,eayunstack/fuel-main