Add delete-tag from @sbesson

Removes tags from repos recursively. Useful after
a failed release attempt.

See: https://gist.github.com/sbesson/6990308
Add log.info call per submodule repo
Add check for 'origin' and 'upstream'
Remove tags locally
Prevent stacktrace on Ctrl-C
Check for tags before removing
Merge pull request #132 from joshmoore/delete-tags

Add delete-tag