Merge tag 'sparks-1.15.1' into develop

1.15.1
push_translations(): use git-up if available before falling back to git pull.
Implement `remote_configuration.reload()` to reload remote Django settings after the remote `git_pull()` to refresh the settings in case they have changed. Without this, we could end up using "old" settings and trying to do things that would fail for obvious reasons.
bump version in setup.py
Merge branch 'release/1.15.2'