Add http://www.wtfpl.net

[client9]

Hi @ryanuber I see you are doing some refactors, so I'll hold off on other pull requests, and just file bugs. Feel free to assign to me anything you wish.

First, to my amazement, http://www.wtfpl.net is used, used in go packages and is semi-legit.

https://tldrlegal.com/license/do-wtf-you-want-to-public-license-v2-(wtfpl-2.0)
http://www.gnu.org/licenses/license-list.html#WTFPL

in fact some of the code loaded into our system has a dependency of some code that uses this license.