Pass the classname prop to the MenuDrop and child Box component (#1627)
Pass the classname prop to the MenuDrop and child Box component (#1627)

* Pass the classname prop to the MenuDrop and child Box component

Signed-off-by: Sarah Allen <be8ec20d52fdf21c23e83ba2bb7446a7fecb32ac@zooniverse.org>

* Use BEM suffix correctly

* Conditionally apply the classname to MenuDrop

Signed-off-by: Sarah Allen <be8ec20d52fdf21c23e83ba2bb7446a7fecb32ac@zooniverse.org>

kylebyerly-hp/grommet