Enable checkstyle rule to verify method names

Enabled checkstyle rule "MethodName" which checks
if method names adhere to a naming convention and
fixed the violations it found.

Change-Id: I87448a1fa857e78f33c42090d485bf21a8986ba7
diff --git a/src/main/java/net/onrc/onos/core/datastore/hazelcast/HZClient.java b/src/main/java/net/onrc/onos/core/datastore/hazelcast/HZClient.java
index 32ff15b..3bfe157 100644
--- a/src/main/java/net/onrc/onos/core/datastore/hazelcast/HZClient.java
+++ b/src/main/java/net/onrc/onos/core/datastore/hazelcast/HZClient.java
@@ -335,7 +335,7 @@
     }
 
     @Override
-    public long VERSION_NONEXISTENT() {
+    public long getVersionNonexistant() {
         return VERSION_NONEXISTENT;
     }