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 to have this? Why not just `get_all_pending_tournaments()` that returns `PendingTournament` objects? Do we specifically need all the JSONs for anything?