Remove useless models init file

optimus/models/__init__.py

-from .optimus import OptimusTransformer
-from .pytorch_transformer import PyTorchTransformer

optimus/models/pytorch_transformer.py

@@ -134,4 +134,4 @@ class PyTorchTransformer(nn.Module):
             x = self.output_norm(x)
             output = self.output(output)
 
-            return output
\ No newline at end of file
+            return output