Update Installation-Requirements.md

cas-server-documentation/planning/Installation-Requirements.md

@@ -8,7 +8,7 @@ title: CAS - Installation Requirements
 Requirements at a glance:
 
 1. [Java](http://www.java.com) >=1.7
-2. [Servlet container](http://tomcat.apache.org/) supporting servlet specification >=2.5
+2. [Servlet container](http://tomcat.apache.org/) supporting servlet specification >=3.0
 3. [Apache Maven](http://maven.apache.org/) >=3.3
 4. Familiarity with the [Spring Framework](http://www.springsource.org/)
 5. Internet connectivity