Bugbear and builtins both using B001

[cas--]

I have not tested the consequences of this but I found googling for B001 that you both picked the same B prefix code in March 2016!

https://github.com/PyCQA/flake8-bugbear#list-of-warnings

[ambv]

As bugbear is an official PyCQA plugin, it would be probably best for the author to change the code used by flake8-builtins.

[gforcada]

@ambv I, as the author, wouldn't mind changing it to X, Y, Z or whatever word, problem is as soon as you get more than 26 plugins... what should we do? https://pypi.org/search/?q=flake8 already reports 423 projects... Is that something that flake8 has already thought about?

I've seen that a plugin can claim not only a word but part of a letter as well, i.e. B0 (giving you B001 to B099orB00`` which gives only B001 to B009), so maybe bugbear could restrict itself a little bit as well...

Anyway, I will make a major breaking release of builtins plugin and I will pick up... A for example.

[gforcada]

@cas-- @ambv flake8-builtins 1.0 is released with the error codes changed to A00X.