a11y improvements on primary navigation menu toggle
Remove style redundancy for menu toggle; cursor pointer is already defined for buttons.
Merge pull request #459 from philiparthurmoore/menu-a11y

a11y improvements on primary navigation menu toggle
Merge remote-tracking branch 'upstream/master' into ja

* upstream/master:
  Remove style redundancy for menu toggle; cursor pointer is already defined for buttons.
  a11y improvements on primary navigation menu toggle