CreateEnvironmentRequest now goes with a CNAME prefix, which will be
equal to the environment name.
This will give us predictable URLs, like
'some-environment-name.elasticbeanstalk.com', every time a new
environment is created.
See:
http://docs.aws.amazon.com/elasticbeanstalk/latest/api/API_CreateEnvironment.html
(CNAMEPrefix)