Edit the username of a user

[tdurieux]

I try to rename my username, the request is accepted.
But when I try to login with my new username the server responses with an unknown user response.
I can login with my old username but I'm not able to retrieve the user info of the user (unknown user).

Request:
GET /api/users/<old_username>/info

{
"name": "not_found",
"description": "No user named <old_username> found"
}

GET /api/users/<new_username>/info

{
"name": "not_found",
"description": "No user named <new_username> found"
}

[satabin]

The renaming should not be allowed.