implement User model and complete current_user method

add User model and implement current_user method
remove pending test from user_spec
Add FactoryGirl and skeleton of tests for projects
add projects#index end point
add end point GET /projects/:id
expose POST /projects end point and add name validation to project
implement GET /projects/:project_id/commits end point
add GET /projects/:project_id/commits/:id end point
WIP, implement POST /projects/:project_id/commits
reject invalid commit POSTs
scope GET /projects to a user_id
add project info in response to POST /projects
respond with errors on invalid POST /projects
respond with created object on POST /projects/:project_id/commits and respond with error messages on bad request
add repo model
rework model associations to include repos and project_repos
Remove pending test
Merge branch 'commits'