yarn linc shouldn't fail because of file-has-not-changed warning

[gaearon]

Just saw this after modifying ESLint config and running yarn linc:

/Users/gaearon/p/react/.eslintrc.js
  0:0  warning  File ignored by default.  Use a negated ignore pattern (like "--ignore-pattern '!<relative/path/to/filename>'") to override

✖ 1 problem (0 errors, 1 warning)

Lint failed for changed files.
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
react)            

We should not treat this particular warning as an error.

[HeroProtagonist]

Hey! I would be interested in taking a stab at this one