User Instance
GET /api/users/355/?format=api
{
"username": "luxim",
"gravatar": "//www.gravatar.com/avatar/2fe3d0f59e8b01e7dbe1527d8b9feaa8?d=wavatar",
"has_key": true
}GET /api/users/355/?format=api
{
"username": "luxim",
"gravatar": "//www.gravatar.com/avatar/2fe3d0f59e8b01e7dbe1527d8b9feaa8?d=wavatar",
"has_key": true
}