phase-3-prep.md

#Phase 3 Prep Spoke with some Tiger Swallowtails and asked them to recommend specific resources that helped them or that they wished they had reviewed before phase 3.

They recommend:

1. Michael Hartl Ruby on Rails Tutorial
2. Rails Intro 1/2: talks.devbootcamp.com
3. Rails Intro 2/2: talks.devbootcamp.com
4. RailsGuide: Getting Started with Rails