tourney import only (WIP)

REST API done for this part, still need to write UI
@garsh0p @jhertz 

no auth integration yet; need to rebase onto master.

(other changes are still on the other branch, which I'll rebase onto this one at some point)
Any reason why the object is a dictionary from `tournament: <real data>`? I think the document should just be `tournament.get_json_dict()` (like in `insert_tournament()`)