The AvatarService.render method would return HTML that included a

user's full name in the alt text, which may not be ideal for privacy. We

now render only the username instead.
However, the method now accepts a template_name parameter so that 3rd

parties can provide their own templating, which may include full names

if they wish.

Ran unit tests against Django 1.6.11 and Django 1.8.19.