Fix User's as_json method
Fix User's as_json method

Fix `as_json` method to merge options hash, if provided, into a default
options hash, giving priority to the passed in options hash.

donaldali/school,roarkm/school,roarkm/school,rails-school/school,donaldali/school,donaldali/school,roarkm/school,rails-school/school,rails-school/school