Ensure final releases are created from git sha

- set version based on build number in case final releases are create out of
  order
- actually add the new release yml file before committing
- don't merge or fetch develop and master before creating the final release
- don't run update script to make sure release uses pipeline sha
- pushes from HEAD are delicately ordered because there may be merge commits
  at each point
- [#73728430]

Signed-off-by: Sheel Choksi <sheelc@pivotallabs.com>