API Team Updates. Fixes #1012

- `/api/v2/team/<team_key>` changed to only return team data (and that is why v2 hasn't been frozen yet)
- `/api/v2/team/<team_key>(/<year>)events` returns a list of event models the team attended in given year (defaults to current year)
- `/api/v2/team/<team_key>/event/<event_key>/awards` returns a list of award models for the team at the event
- `/api/v2/team/<team_key>/event/<event_key>/match` returns a list of match models for the team at the event

TODO: Put years_participated somewhere. I don't to put it in `/api/v2/team/<team_key>` because that endpoint returns a Team model, as does `/api/v2/event/<team_key>/teams`, so I want to keep them consistent. But calculating years_participated requires quite a few DB accesses. We could just do `/api/v2/team/<team_key>/years_participated`, but it seems excessive to have it's own endpoint. Ideas?