Add support for `eslint-config-react-app`

[dannyc5]

create-react-app is a popular automated build tool for React. It uses its own eslint config by default: eslint-config-react-app

Could you add support for this?

Supporting this would also require updating the following plugins:

babel-eslint@7.0.0
eslint@3.8.1
eslint-plugin-flowtype@2.21.0
eslint-plugin-import@2.0.1
eslint-plugin-jsx-a11y@2.2.3
eslint-plugin-react@6.4.1

FWIW, I also opened a PR at #168 that adds the dependencies. I've also tested it out locally.