Add migration, model, factory, and spec file for Organization
Add migration, model, factory, and spec file for Campaign
add presence and unique validations to Organization
Add migration, model, factory, and spec file for Donor
Add migration, model, factory, and spec file for Item
Add migration, model, factory, and spec file for Pledge
Add migration, model, factory, and spec file for Request
create associations between models
make aliases for Item model
Modify database associations
-Pledge is now a join table for Campaign and Item
-Pledge is now a join table for Campaign and Donor
Fix bugs in Organization model
Fix bugs in campaign, pledge, request models
Add seed file
Fix merge conflicts
Merge pull request #19 from spring-peepers-2014/migrations

Finish database migrations and models. Add seed files.