Add uib prefix to fix sign up modal, closes #145
Add uib prefix to fix sign up modal, closes #145

I missed a `modalInstance` in the signup modal. I'm okay with a certain
amount of regression as I develop new features, but it sucks to break
signups.

Thanks a bunch to @erispoe for reporting!

levelonedev/gokibitz,neagle/gokibitz,neagle/gokibitz,levelonedev/gokibitz