Races join

[kumy]

User story

As a GeoKrety.org fan I want to be able join a race so that my GeoKrety can participate.

Acceptance criteria

• Any authenticated user MAY be able to join the race
• Anonymous users CANNOT join races
• The GeoKret to register MUST belongs to the connected user
• Archived GeoKret CANNOT be registered
• The race MUST NOT be ended to register
• Password MUST be provided for private races
• The organizer CAN join his private races without password
• Race players CAN join joined private races without password
• An admin CAN join private races without password
• An admin CAN join any GeoKrety to races
• An admin CAN join ended races