fixes failing rspec tests and adds factory_girl

 - retrofitted tests to existing functionality, which is likely broken in a few places (e.g. api calls returning json of the form `{endowment: {endowment: {name: "some name", ...}}}` )
 - switched some tests to pending that need to be rewritten (e.g. the donate api call was replaced with a one_time_donation action that behaves differently)