Fix for https://github.com/diasjorge/redmine-cli/issues/2

Thanks for writing redmine-cli. I've found it to be useful so far, and hope to add some additional functionality as I need it.

This is a fix for https://github.com/diasjorge/redmine-cli/issues/2 . Redmine includes additional attributes in <issues> element that confuse ActiveResource. Workaround was copied from http://community.pivotaltracker.com/pivotal/topics/activeresource_client_throws_error .

Cheers!