add users to icpc github organization, or modify team membership & administration

[wmacevoy]

The identified chief judge of the region and regional director should have administrative rights to manage the teams & in their organization.

If you need a new member of this org to add to your team, please create an issue here with:

1. GitHub user to add (Real name and user name)
2. Team(s) to add them to.
3. Authority (description of why you have the authority to do this).