Updates to API v0.4 (see changes in full msg below)

* API spec now qualifies for PG rating
* Updated user attributes to include password (required on init.
  creation, updated with PATCH thereafter)
* Updates all DELETE requests to return 204 (as discussed)
* Fleshed out /roles endpoint; search, PUT, PATCH, and DELETE now
  properly documented
* Fixed several validation errors in the sample responses (which
  I noticed because Postman refused to pretty-print the response
  body--try http://jsonlint.com)
* Closes #4, #5, #6
Fixed several Blueprint validation issues caught by Apiary
Updated header to "API 0.4"; updated HOST
Fixed a stupid typo (missing ") in GET /role
Merge pull request #11 from ernstki/master

Close Role endpoint issues and bump API to 0.4