added security service latch

Added Latch service: https://latch.elevenpaths.com

ruby verify.rb 
No errors. You're good to go!
![facepalm](http://my350z.com/forum/images/smilies/facepalm42550987.gif)
[New Providers](https://github.com/jdavis/twofactorauth/blob/master/CONTRIBUTING.md#new-providers)
Sorry. My fault, didn't check that.