Release 0.0.12

Merge the 0.0.12 (sprint12) release from devel.

This release includes the improvements found in the `sprint12` milestone:
https://github.com/18F/midas/issues?milestone=4&state=closed

Most notably:
- Forgot password UI and API
- 508 improvements
- Documentation updates (fixes and OS X install)
- Search API bug fixes
- UI bug fixes