Lots of updates!

• [new] Add rule anchor-is-valid. See documentation for configuration options. Thanks @AlmeroSteyn.
• [breaking] href-no-hash replaced with anchor-is-valid in the recommended and strict configs. Use the invalidHref aspect (active by default) in anchor-is-valid to continue to apply the behavior provided by href-no-hash.
• [breaking] Removed support for ESLint peer dependency at version ^2.10.2.
• [update] The rule label-has-for now allows inputs nested in label tags. Previously it was strict about requiring a for attribute. Thanks @ignatiusreza and @mjaltamirano.
• [update] New configuration for interactive-supports-focus. Recommended and strict configs for now contain a trimmed-down whitelist of roles that will be checked.
• [fix] Incompatibility between node version 4 and 5. Thanks @evilebottnawi.
• [fix] Missing README entry for media-has-caption. Thanks @ismail-syed.
• [fix] README updates explaining recommended and strict configs. Thanks @Donaldini.
• [fix] Updated to [email protected], which includes new ARIA 1.1 properties. Previously, the aria-props rule incorrectly threw errors for these new properties.