cosmos.py should tell you your API key has insufficient rights

When you try to run bootstrap-ci.py with an API key that has Cloud Customer rights, but no Customer rights, you get this failure:

./ci-bootstrap.py --create-droplet
Creating droplet
Created droplet id: 1998
Waiting for droplet 1998 to reach running state...
Creating domain record
Traceback (most recent call last):
  File "./ci-bootstrap.py", line 159, in <module>
    update=True)
  File "/home/users/maarten/projects/openappstack/bootstrap/test/cosmos.py", line 75, in create_domain_record
    record_type=record_type)
  File "/home/users/maarten/projects/openappstack/bootstrap/test/cosmos.py", line 142, in get_domain_record_by_name
    records = get_domain_records(domain=domain)
  File "/home/users/maarten/projects/openappstack/bootstrap/test/cosmos.py", line 156, in get_domain_records
    response = request_api('domains/{0}/records'.format(domain))
  File "/home/users/maarten/projects/openappstack/bootstrap/test/cosmos.py", line 56, in request_api
    response.status_code, response.text)

Because the API key has insufficient rights to make DNS entries. This error should be caught and give the user a nice error message telling them to add Customer rights to their API key in the Cosmos Service Centre