updated db seeds to ensure uniqueness of users
added hirb and bullet for debugging
use eager loading to prevent n+1 problems
refactored ability model to use hash conditions
pagination works for real now
added indexes to foreign keys in db for faster queries
remove unnecessary eager loading
Merge pull request #41 from valerie-roske/query-optimization

#352: Valerie: Query optimization
Add start_date and graduated fields to user and AC factories