Better error responses from register method
Rename register to join. Add documentation for join method
Properly create initial game state. Player translation works
Detect if user has already made a move this round
Check to make sure player has joined the game
Set initial location of bullet. Allow setting 'override' header to skip sanity checks.
Detecting end of turn should be working. Move bullets to an array of old turn states so that the current state can be updated in the next turn without worrying about resetting it
Reset player moved state at the end of each turn so that they can move again