v3.0 Tracking

[jstcki]

• [ ] Bump eslint to v2
• [ ] Bump eslint-plugin-react to v4
• [ ] Bump babel-eslint to v6 (once it works with eslint v2)
• [ ] Add eslint-plugin-immutable (see #7)

[jstcki]

Closing again, using the 3.0 milestone instead to group individual issues.