Revise new developer checklist

Created by: jwillenbring

CC: @trilinos/framework

Description:

The new developer checklist needs to be revised. In particular, to be up-to-date with the move to GitHub. Mentors can now decide when new students should get push access.

https://software.sandia.gov/trilinos/developer/sqp/checklists/newTrilinosDeveloper201508.txt

Tasks:

1. Initial update of checklist [Done]
2. Have set out for review and collect updates ... IN PROGRESS ...
3. Publish checklist to final location ...