Team application feature

[joeboppell]

Right now, applicants can only apply by themselves. Most hackathons allow applying as a team (usually increases your chances of getting in).

Here's how the new feature should work

1. Every applicant applies like normal (every person on the team needs to apply individually) - frontend-template
2. Allow them to create teams like they normally can during the hackathon - frontend-template and apiv3
3. If they join a team with at least one other person, they will be synced on teams.hackpsu.org, where we will grade them. - teams (repo doesn't exist yet)
4. There will be another tab on the participant applications page where team applications will show up, just like the Penn State and Other pages - adminv2
5. When a team is accepted, we need a route to accept teams in bulk, and send them emails accordingly - apiv3