fix following issue.
    1. click button go to login page, form should not have action for
    ng-click
    2. create checkout working well now.
    3. the attendees parameters should be object with id attribute
    3. remove uneccessary debug info
add OPTIONS request to fix the CROS request
reconstruct the service code
fix the missing creator_id issue
add the error mesage in the return message
and the OPTIONS method to fix the CROS request
fix the wrong attributte issue