Add GetAddExistingUserToExistingSpace to Config
Add GetAddExistingUserToExistingSpace to Config

[#166013088](https://www.pivotaltracker.com/story/show/166013088)

cloudfoundry/cf-smoke-tests,cloudfoundry/cf-smoke-tests,cloudfoundry/cf-smoke-tests,cloudfoundry/cf-smoke-tests