bootstrap affix for widgets

main.js

				var StickyWidget = $('.sidebar .widget:last-child');

				if(StickyWidget){
					var trigger = StickyWidget.offset().top - $('#primary-masthead').height();
					StickyWidget.affix({
						offset: {
							top: function(){
								return trigger;
							},
							bottom: function () {
								return (this.bottom = $('.footer-wrap').outerHeight(true))
							}
						}
					});
				}