Catch exceptions to return false on Pivotal::Base#update_attributes
Catch exceptions to return false on Pivotal::Base#update_attributes

RestClient returns/yields a RestClient::Response object only when the HTTP response code is ~200-399.  400-level and 500-level responses raise RestClient::Exception errors, which must be caught separately.
flaviogranero/git-pivotal,trydionel/git-pivotal