Add extra contributors.
Add extra contributors.

lowjoel/activerecord-userstamp,lowjoel/activerecord-userstamp,jparr/activerecord-userstamp,reger/activerecord-userstamp,putneyj/activerecord-userstamp,lowjoel/activerecord-userstamp,reger/activerecord-userstamp,jparr/activerecord-userstamp,reger/activerecord-userstamp,jparr/activerecord-userstamp,putneyj/activerecord-userstamp,putneyj/activerecord-userstamp