Support --label for scheduling lists



Pull request for [Support --label for scheduling lists](https://trello.com/c/z2fDNjku/1833-support-label-for-scheduling-lists).

    
Huh, won't clone the repo until there are tabs! :-1: 

(Sounds bit fanatic, but actually, even opening and saving such files in my editor would make very ugly diffs... And I am not going to change my space/tab settings, because tabs just ain't right in Python.)