handle case of "attr" decorators with arguments

[zadamah]

Fixes / new features

• adds support for attrs package decorators with arguments, completes fix by @brycepg PyCQA/astroid
  Add Transform Plugin for attr to fix false positives due to instance attribute rewriting #462
• I added an example issue resolved by this in Support the "attrs" library pylint#1698

[rogalski]

Looks good to me :) .

@PCManticore lack of coverage check for PRs is intentional?

[zadamah]

thanks for the review Łukasz :)

[PCManticore]

Thank you @zadamah
@rogalski Nope, I'm not sure what happens with coveralls. It is enabled and it is configured to use the status API for PRs. Going to take a closer look in the weekend.

[joshburkart]

Thank you for doing this!!

[zadamah]

Happy to hear that it is useful to you too 😃
I Hope it'll be in the next pylint release (if it's not already)