Merge pull request #3073 from bitcloud/fix-datetime-example

fix date format in example generator

Author: wing328

modules/swagger-codegen/src/main/java/io/swagger/codegen/examples/ExampleGenerator.java

@@ -93,9 +93,9 @@ protected Object resolvePropertyToExample(String mediaType, Property property, S
                 };
             }
         } else if (property instanceof DateProperty) {
-            return "2000-01-23T04:56:07.000+0000";
+            return "2000-01-23T04:56:07.000+00:00";
         } else if (property instanceof DateTimeProperty) {
-            return "2000-01-23T04:56:07.000+0000";
+            return "2000-01-23T04:56:07.000+00:00";
         } else if (property instanceof DecimalProperty) {
             return new BigDecimal(1.3579);
         } else if (property instanceof DoubleProperty) {