Combine `package` and `images` stages in pipeline
With Ubuntu 16.04 job split off to an earlier stage, there is no technical reason for rest of the package building and Docker image building to be done sequentially, other than having a logical separation between the two operations. We can have Docker build happen parallely with package builds for other OSs. If we were to merge there two stages, we may be able to save few more minutes on the pipeline.
We may already have to move QA image build to an early stage - https://gitlab.com/gitlab-org/release/framework/issues/80
cc @gitlab-org/distribution WDYT? (I can agree if we want to keep them separate for clarity, but I prefer shorter pipeline more.