bug: pl_bolts.losses raises AttributeError

[akihironitta]

🐛 Bug

On the current master branch, using pl_bolts.losses after import pl_bolts gives an error (though from pl_bolts import losses works fine). pl_bolts.transforms also gives the same error.

As far as I understand, this error is raised because pl_bolts/__init__.py doesn't have import statements for losses and transforms.

To Reproduce

Run the following script

import pl_bolts
print(pl_bolts.models)
print(pl_bolts.losses)  # print(pl_bolts.transforms) also fails.

to get the below error:

<module 'pl_bolts.models' from '/home/nitta/work/pytorch-lightning-bolts/pl_bolts/models/__init__.py'>
Traceback (most recent call last):
  File "main.py", line 3, in <module>
    print(pl_bolts.losses)  # print(pl_bolts.transforms) also fails.
AttributeError: module 'pl_bolts' has no attribute 'losses'

Expected behavior

Run the above example and get the following output:

<module 'pl_bolts.models' from '/home/nitta/work/pytorch-lightning-bolts/pl_bolts/models/__init__.py'>
<module 'pl_bolts.models' from '/home/nitta/work/pytorch-lightning-bolts/pl_bolts/losses/__init__.py'>