Fix some import errors

ml-agents/mlagents/trainers/agent_processor.py

 
 from mlagents.trainers.trainer import Trainer
 from mlagents.trainers.trajectory import Trajectory, AgentExperience
-from mlagents.envs.brain import BrainInfo
+from mlagents.trainers.brain import BrainInfo
-from mlagents.envs.action_info import ActionInfoOutputs
+from mlagents.trainers.action_info import ActionInfoOutputs
 
 
 class AgentProcessor:

ml-agents/mlagents/trainers/tests/test_ppo.py

 from mlagents.trainers.ppo.trainer import PPOTrainer, discount_rewards
 from mlagents.trainers.ppo.policy import PPOPolicy
 from mlagents.trainers.trajectory import trajectory_to_agentbuffer
-from mlagents.envs.brain import BrainParameters
+from mlagents.trainers.brain import BrainParameters
 from mlagents.envs.environment import UnityEnvironment
 from mlagents.envs.mock_communicator import MockCommunicator
 from mlagents.trainers.tests import mock_brain as mb