fix(tabs): md-center-tabs should work now

Author: Robert Messerle

src/components/tabs/js/tabsController.js

@@ -32,7 +32,7 @@ function MdTabsController ($scope, $element, $window, $mdConstant, $mdTabInkRipp
   defineBooleanAttribute('swipeContent');
   defineBooleanAttribute('noDisconnect');
   defineBooleanAttribute('autoselect');
-  defineBooleanAttribute('centerTabs');
+  defineBooleanAttribute('centerTabs', handleCenterTabs);
 
   //-- define public properties
   ctrl.scope = $scope;
@@ -153,6 +153,10 @@ function MdTabsController ($scope, $element, $window, $mdConstant, $mdTabInkRipp
     updateInkBarStyles();
   }
 
+  function handleCenterTabs (newValue) {
+    ctrl.shouldCenterTabs = shouldCenterTabs();
+  }
+
   function handleMaxTabWidth (newWidth, oldWidth) {
     if (newWidth !== oldWidth) {
       $mdUtil.nextTick(ctrl.updateInkBarStyles);