Service Broker Changes with bump to vcap-common gem

 - Add support for optional provider for brokered services

 - Refactoring to reuse bulk of code from catalog manager
   in base-gem

 - Update service broker specs

 - Fix Rakefile for CI

 - Bump vcap-common:
   git shortlog fd6b6d91..055964f622
   Dr Nic Williams (1):
      VCAP::Component.register returns its configuration

   Harshawardhan Gadgil (1):
      Add (optional) user guid and space guid to gateway provision request

   Jesse Zhang (3):
      Move rspec from Gemfile to gemspec
      Add tests for SDSClient
      Only use em-http-request on reactor_thread

   Pieter Noordhuis (3):
      Relax yajl-ruby dependency
      Make varz thread-aware
      Bump patch version

Change-Id: I49b66abccc3aa91700510936af4e6f661e4be2a3