Add missing data namespace for dropdown

js/dropdown.js

@@ -123,9 +123,9 @@
   $.fn.dropdown = function (option) {
     return this.each(function () {
       var $this = $(this)
-      var data  = $this.data('dropdown')
+      var data  = $this.data('bs.dropdown')
 
-      if (!data) $this.data('dropdown', (data = new Dropdown(this)))
+      if (!data) $this.data('bs.dropdown', (data = new Dropdown(this)))
       if (typeof option == 'string') data[option].call($this)
     })
   }