Squashed 'rdoupdate/utils/' changes from f4825a7..39e868b

39e868b Don't print `git remote show` output
cee986d Add Git.ref_exists()
e18e60f Add push-updates action
3fa01dc Fix IncompleteChangelog error message
ad00760 Ensure only one logging handler
77beb6d Make rpm dep optional

git-subtree-dir: rdoupdate/utils
git-subtree-split: 39e868baf8bebee61c394e0480bccd716986bdbb
Merge commit 'e20a162ae39c7a7b56bed5aa9f9c037d8acec986'
Support multiple pluggable build sources
Add download action