Refactors and cleans up dead code in GitHub module (spinnaker#137)

* Refactors and cleans up dead code in GitHub module
* Added rate limit header info

Adds pagination support to Github UserRolesProvider (spinnaker#130)

Added more logging during user role sync (spinnaker#129)

rotated credentials

Rolls deps version forward, which pulls back Spring Boot back to 1.2.8 (

spinnaker#110)

Adds service account endpoints + ability for fiat-api module to verif…

…y service account authorization. (spinnaker#108)

Upgrades to Spring Boot 1.4 by way of a spinnaker-deps bump (spinnake…

…r#106)

Kork bump (spinnaker#105)

Rm component (spinnaker#104)

Makes fiat-api module Gate friendly. Most notably this PR merges in G…

…ate's FiatService endpoints into fiat-api's shared version. (spinnaker#103)