Standalone UAA uses Spring Boot

[joshuatcasey]

Requires a lot of changes!

• Unit tests do pass
• TBD if integration tests pass

Can't merge yet because the BOSH release isn't prepped for Spring Boot.

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/170267828

The labels on this github issue will be updated when the story is started.

[joshuatcasey]

Closing since it's been open too long