Merge pull request #125 from a-lucas/master

fixes #61

Author: jbrowning

src/tabs/tabs.js

@@ -201,8 +201,11 @@ angular.module('mm.foundation.tabs', [])
         }
 
         scope.$watch('active', function(active) {
+          if( !angular.isFunction(setActive) ){
+            return;
+          }
           // Note this watcher also initializes and assigns scope.active to the
-          // attrs.active expression.
+          // attrs.active expression.          
           setActive(scope.$parent, active);
           if (active) {
             tabsetCtrl.select(scope);