Upgrade to Spring Boot 1.0.0 GA

 - Remove use of @EnableTransactionManagement, as this is Now implicitly
   enabled in Spring Boot 1.0.0 GA. See spring-projects/spring-boot#576

 - Note that this change also implicitly upgrades to Spring Framework
   4.0.3 GA as well

 - Replace use of /libs-milestone repository for /libs-release as we now
   no longer depend on any non-GA artifacts

 - Update AuthorizationTests to reflect that the /shutdown actuator
   endpoint is now disabled by default in 1.0.0 GA