[PyTorchLightning/pytorch-lightning] Add deprecation path for renamed training...

[PyTorchLightning/pytorch-lightning] Add deprecation path for renamed training type plugins (#11227)

Summary:
### New commit log messages
  4eede7c30 Add deprecation path for renamed training type plugins (#11227)

Reviewed By: edward-io, daniellepintz

Differential Revision: D33409991

fbshipit-source-id: 373e48767e992d67db3c85e436648481ad16c9d0

examples/source_separation/lightning_train.py

@@ -19,7 +19,7 @@ import torch
 import torchaudio
 from pytorch_lightning import LightningModule, Trainer
 from pytorch_lightning.callbacks import ModelCheckpoint, EarlyStopping
-from pytorch_lightning.plugins import DDPStrategy
+from pytorch_lightning.strategies import DDPStrategy
 from torch import nn
 from torch.optim.lr_scheduler import _LRScheduler
 from torch.utils.data import DataLoader