Added deprecated flag to rule meta object

[wagerfield]

Please add the deprecated flag to the meta object for all deprecated rules.

This is the documented way of declaring a rule as being deprecated.

http://eslint.org/docs/developer-guide/working-with-rules#rule-basics

module.exports = {
  meta: {
    deprecated: true
  },
  create: function() {
    ...
  }
}

[hzoo]

Do you want to make a pr for this?

[wagerfield]

Sure thing.