Example: ray_ddp_sharded_example.py (#153)

Fix on_train_epoch_end() hook usage.
From PTL interface definition, we don't need the additional `outputs` arg.

Author: chongxiaoc

ray_lightning/examples/ray_ddp_sharded_example.py

@@ -20,7 +20,7 @@ def on_train_epoch_start(self, trainer, pl_module):
         torch.cuda.synchronize(trainer.root_gpu)
         self.start_time = time.time()
 
-    def on_train_epoch_end(self, trainer, pl_module, outputs):
+    def on_train_epoch_end(self, trainer, pl_module):
         torch.cuda.synchronize(trainer.root_gpu)
         max_memory = torch.cuda.max_memory_allocated(trainer.root_gpu) / 2**20
         epoch_time = time.time() - self.start_time