heroku/heroku — pull request #971 by nicolasleger (2013-12-14 11:30:18+00:00)
Title: Add heroku config:rename command

Add `heroku config:rename OLD_KEY NEW_KEY` command by setting the new with the value and unsetting the old.
I could have use set and unset but it would appears as 2 different commands in logs, making 2 releases and restarted the app twice.