Update to support eslint2

[tanepiper]

In Votes For Schools, were getting:

  3:1  error  Rule 'no-empty-label' was removed and replaced by: no-labels                 no-empty-label
  3:1  error  Rule 'space-before-keywords' was removed and replaced by: keyword-spacing    space-before-keywords
  3:1  error  Rule 'space-after-keywords' was removed and replaced by: keyword-spacing     space-after-keywords
  3:1  error  Rule 'space-return-throw-case' was removed and replaced by: keyword-spacing  space-return-throw-case

If we upgrade eslint to 2. Rules defined to not work with this version.