Bootstrap 3 is still at RC, but I was just trying to implement it. I couldn\'t figure out how to put a sub menu class. Even there is no class in css and even the new docs do
Comment to Skelly's really helpful workaround: in Bootstrap-sass 3.3.6, utilities.scss, line 19: .pull-left has float:left !important. Since that, I recommend to use !important in his CSS as well: