Annotates PetitionSignature model, factory, and spec
Validates presence of Petition#creator_id
Creates attr_accessible, validations, and associations for PetitionSignature model
Updates File and class names to reflect PetitionSignature model
Finished associations for PetitionSignature join table
Updates user model per prototype w/migration
Updates Petition model and table per prototype w/migration
Adds inclusion validations for Petitions and User models
Fixes User model and seed file
Adds PetitionSignatures on the Petition show page. Woot!
Adds Petition.includes(:signatures) to avoid n+1
Changes Petition Summary in Petition index view
Changes seed file to include the construction of PetitionSignatures
Fixes victory before merging back to master