bump bbs
bump bbs

[finishes #101145994]

Submodule src/github.com/cloudfoundry-incubator/bbs 4522fa6..373fe5f:
  > Cleanup handler helpers
  > Convert proto errors to system errors on client.go
  > RPCIfy ConvergeTasks request
  > RPCify task lifecycle requests
  > RPCify StartTask request
  > RPCify TaskByGuid request
  > RPCify Tasks request
  > Explode all TaskDB requests into individual arguments
  > RPCify DesireTask
  > RPCify DesiredLRPByProcessGuid
  > RPCify DesiredLRPs list request
  > RPCify all of the ActualLRP Lifecycle
  > RPCify RemoveActualLRP
  > RPCify ActualLRPGroupByProcessGuidAndIndex
  > Make ActualLRPGroupsByProcessGuid RPC-like and not RESTful.
  > Explore request arguments in evacuation DB methods
  > RPCify RemoveEvacuatingActualLRP
  > Make ActualLRPGroups call RPC-like instead of RESTful
  > RPCify Domains
  > RPCify UpsertDomain
  > Rename integration tests to not rely on path/method

Signed-off-by: Luan Santos <509a85c757dc22c0257f4655fb3fb682d42f965b@pivotal.io>

cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release