feat(datepicker): remove unnecessary scope.ngModelOptions

Author: Jeffrey Barrus

Diff for: src/datepicker/datepicker.js

@@ -611,9 +611,6 @@ function(scope, element, attrs, $compile, $parse, $document, $rootScope, $positi
     datepickerEl = angular.element(popupEl.children()[0]);
     datepickerEl.attr('template-url', datepickerTemplateUrl);
 
-    scope.ngModelOptions = { $options: angular.extend({ allowInvalid: false }, ngModelOptions) };
-    datepickerEl.attr({'ng-model-options': 'ngModelOptions'});
-
     if (isHtml5DateInput) {
       if (attrs.type === 'month') {
         datepickerEl.attr('datepicker-mode', '"month"');