tiered permission model

[bobheadxi]

The current Rocket only has admins and everyone else - it's probably more flexible to have an additional lead position that has permissions like team and repo creation. Something like:

• admin: create, delete, read
• lead: create, read
• everyone else: read

[rwblickhan]

This is part of our roadmap (in fact if you look at permissions.py you'll see that TEAM_LEAD is one of the three possible permissions levels) though I'm noticing a bit of confusion about that - I didn't explicitly write it down in our docs, so I may update those at some point (and close this when I do).

[rwblickhan]

This is already part of our data model and included more specifically in other tickets; closing.