Update minimum required schema to 3.1.

samples/tutorial/src/main/webapp/WEB-INF/applicationContext-security.xml

@@ -9,7 +9,9 @@
     xmlns:beans="http://www.springframework.org/schema/beans"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
-                        http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.0.xsd">
+                        http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.1.xsd">
+
+    <debug />
 
     <global-method-security pre-post-annotations="enabled">
         <!-- AspectJ pointcut expression that locates our "post" method and applies security that way