Update service broker (bump vcap_common)

 - git shortlog 055964f622..68d86f57fb
   Harshawardhan Gadgil (2):
      Add (optional) provider to GatewayProvisionRequest
      Add (optional) org-guid to Gateway provision request

Change-Id: I696c35cb553010f877c34990464242ac353b3ab9
Merge git://github.com/cloudfoundry/vcap-services