Pass balrog_username down to scripts.
Merge branch 'master' of git://github.com/mozilla/build-buildbotcustom into tbirdbld-balrog
Merge branch 'master' of git://github.com/mozilla/build-buildbotcustom into tbirdbld-balrog
Merge branch 'tbirdbld-balrog' into balrog-release-pusher
Pass balrog username.