eslint v4 support

[ljharb]

Note: I filed this issue within minutes of eslint v4.0.0 being released.

eslint-config-airbnb and eslint-config-airbnb-base do not yet support eslint v4.

If it is easy/possible to support both v3 and v4, we will release a non-major bump of both packages that does so, before releasing a major bump that only supports v4.

This will likely take a few weeks at a minimum.

Please do not file additional issues and do not file pull requests attempting to add support - please, instead, continue to use eslint v3 until such time as our configs support v4.

Peer Dep eslint combined v3 and v4 support released:

• eslint-plugin-import issue | PR | released as v2.6.0
• eslint-plugin-react issue for v7.1.0 release
• eslint-plugin-jsx-a11y issue | PR | release (v5.1.0 and v6)
• eslint-find-rules issue | released as v30.1
• update and publish the base config
• update and publish the main config