Update pom.xml

Prep for next release (2.5.4.0( by setting version to 2.5.4.0-SNAPSHOT.

Author: kwwall

pom.xml

@@ -3,7 +3,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>org.owasp.esapi</groupId>
     <artifactId>esapi</artifactId>
-    <version>2.5.3.0</version>
+    <version>2.5.4.0-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <distributionManagement>