implement the unit tests for Gittip.trim
implement the unit tests for Gittip.trim

I'm not sure how to get the integration tests working :<

eXcomm/gratipay.com,mccolgst/www.gittip.com,gratipay/gratipay.com,mccolgst/www.gittip.com,eXcomm/gratipay.com,mccolgst/www.gittip.com,eXcomm/gratipay.com,studio666/gratipay.com,gratipay/gratipay.com,studio666/gratipay.com,mccolgst/www.gittip.com,gratipay/gratipay.com,eXcomm/gratipay.com,gratipay/gratipay.com,studio666/gratipay.com,studio666/gratipay.com