Rename create_user to participant
Rename WebUser.record_goal to WebUser.goal
Obsolete all forms of record_goal
Move from get_enrollment to get_alternative api
Introduce enroll() call
set_alternative api to match get_alternative
Fix passing gargoyle key through
Update documentation
Make sure control group is created
Documentation fixes
Use constants for test variables
Merge pull request #89 from mixcloud/code_api

Serverside API for enrollment