Environment for Cleanup about sequential_social_dilemma_games

[eugenevinitsky]

@natashamjaques
A new environment consists of five items that must be implemented.:
def custom_reset(self):
"""Reset custom elements of the map. Called every reset."""
raise NotImplementedError

def custom_action(self, agent):
    """Implement actions that are not move or turn"""
    raise NotImplementedError

def custom_map_update(self):
    """Custom map updates that don't have to do with agent actions, for example firing and apple spawning"""
    raise NotImplementedError

def clean_map(self):
    """Clean map of elements that should be removed. Executed every step. Example includes removing fired beams."""
    raise NotImplementedError

def execute_custom_reservations(self):
    """Execute reserved slots that do not have to do with moving, for example, spawn the apples and fire the beams."""
    raise NotImplementedError

def setup_agents(self):
    """Constructs all the agents in self.agent"""
    raise NotImplementedError