Update CAS client to 3.1.12

cas/cas.gradle

@@ -5,7 +5,7 @@ dependencies {
             "org.springframework:spring-context:$springVersion",
             "org.springframework:spring-beans:$springVersion",
             "org.springframework:spring-web:$springVersion",
-            "org.jasig.cas.client:cas-client-core:3.1.11",
+            "org.jasig.cas.client:cas-client-core:3.1.12",
             "net.sf.ehcache:ehcache:$ehcacheVersion"
 
     provided 'javax.servlet:servlet-api:2.5'