Eslint config defaults

[taion]

Closes #522.

@justjake: I can see why you didn't want to do this. This was a lot more time-consuming than I had anticipated.

It's split up into 3 commits:

1. Bring in the rules from eslint-config-defaults and plug them in.
2. Account for the mismatches against what's currently in 0.0.9.
3. Update for changes in latest versions of ESLint and eslint-plugin-react.

[justjake]

can you not just reference them relatively? I think that issue was why I was constructing a rules object instead of just extending 'base' previously. Can eslint resolve these when running npm run lint without special linking magicks?

[taion]

npm run lint didn't work when referencing them relatively. It interpreted them as the names of eslint-config-* packages for some reason.

It's possible that doing something like https://github.com/walmartlabs/eslint-config-defaults/blob/master/package.json#L34 involving making main not be index.js could work, but I didn't try it, because this approach seemed tolerable.

[ljharb]

I believe all extends in eslint have to be named starting with "eslint-config", or a scoped package with the name ending in "/eslint-config".

[taion]

@ljharb I have no clue - the relative imports work here: https://github.com/airbnb/javascript/pull/526/files#diff-ca246d3b4ba146243647f872c0e7e8d1R3, but they didn't work on index.js. ¯_(ツ)_/¯

[justjake]

SO GOOD! I'm very excited for this; will make it easy to fix things like #496 in the next few PRs.

@hshoff you should look this over and make sure you're ok with this.
@baer how does this satisfy #366 for you? Is the structure similar enough? Or do you want index.js files in folders?

[hshoff]

Lovely! Love open source. Thanks @taion! 🍻

[baer]

This is super awesome guys! Nice work!