[Feature] Support topk customizing in models/heads/base.py

[jamiechoi1995]

Support topk customizing in models/heads/base.py

[kennymckormick]

To merge this PR, please help to fix the lint problem.

[jamiechoi1995]

yapf.....................................................................Failed
- hook id: yapf
- files were modified by this hook

I have no idea why yapf failed, can you please help me take a look of it? @kennymckormick

[dreamerlin]

yapf.....................................................................Failed
- hook id: yapf
- files were modified by this hook

I have no idea why yapf failed, can you please help me take a look of it? @kennymckormick

I try to modify your PR but failed, since Github "removed the Support for password authentication on August 13, 2021", and we can only use a personal access token now.

You can refer to https://github.com/open-mmlab/mmcv/blob/master/CONTRIBUTING.md to install pre-commit and run pre-commit run --all-files to fix it.

Or if you want, I can renew a PR for it

[kennymckormick]

Just as @dreamerlin said, you need to run pre-commit run --all-files locally. You can try it next time, I have fixed the lint problem of this PR.

[jamiechoi1995]

Thank you @kennymckormick @dreamerlin , I try to install pre-commit but failed due to the rbenv installation. I will run pre-commit before my next commit. Thank you for your help 👍