Include list of people who use / don't use a feature

[landlessness]

It would be nice to see on a page like this http://www.apiatlas.com/verbs/head the avatars of who uses the feature and who doesn't.

[13protons]

Creating a user now makes note of gravatar urls so they can be looked up more easily in the future.

I'll still need to write a migration for the handful of users that signed up on day one - or do it by hand :/