deploy: Update to fit the current requirements

Particularly instead of triggering the same job all the time, every
environment has its own job assigned.
Finished feature 61564576/deploy-to-client-staging.
pivotal: Fix Story.is_unstarted to include unscheduled
release: Ignore stories with certain labels

Namely 'wontfix', 'dupe' and 'cannot reproduce'.
Finished feature 62619698/wontfix-dupe-etc.
release finish: Trigger deployment by default
Finished feature 61564576/deploy-to-client-staging.
Rename release {finish,deliver} to {stage,finish}

This commit is somehow a mess because I had to fix some forgotten flags
that were not being used any more, but I hope this brings it to a less
messy state than before :-)
Finished feature 62704716/rename-release-subcommands.
Merge branch 'develop' into release/1.2.1

Conflicts:
	gitflow/bin/__init__.py