Use NamedTuples instead of attrs classes

ml-agents/mlagents/trainers/agent_processor.py

 
             experience = AgentExperience(
                 obs=obs,
-                group_status=group_statuses,
                 reward=step.reward,
                 done=done,
                 action=action_tuple,
                 interrupted=interrupted,
                 memory=memory,
+                group_status=group_statuses,
+                group_reward=step.group_reward,
             )
             # Add the value outputs if needed
             self.experience_buffers[global_id].append(experience)

ml-agents/mlagents/trainers/trajectory.py

 from typing import List, NamedTuple
 import itertools
-import attr
 import numpy as np
 
 from mlagents.trainers.buffer import AgentBuffer
 
-@attr.s(auto_attribs=True)
-class GroupmateStatus:
+class GroupmateStatus(NamedTuple):
     """
     Stores data related to an agent's teammate.
     """
     done: bool
 
 
-@attr.s(auto_attribs=True)
-class AgentExperience:
+class AgentExperience(NamedTuple):
-    group_status: List[GroupmateStatus]
     reward: float
     done: bool
     action: ActionTuple
     interrupted: bool
     memory: np.ndarray
+    group_status: List[GroupmateStatus]
+    group_reward: float
 
 
 class ObsUtil: