translation bot publishes incomplete translations on the translation_completed branches

When a translation file:

• Gets completed
• Gets outdated and is not complete anymore (maybe gets new strings added)

It still appears on https://gitweb.torproject.org/translation.git/log/?h=BRANCH_completed

This is because the transifex client skips the update, but the file is still there in the folder:

https://gitweb.torproject.org/translation-tools.git/tree/update_translations#n30

I need to change this so the not-completed-anymore languages dissapear from the folder (probably with a blunt rm *)