Changed release version for maven.

Author: mangrish

README.md

@@ -26,7 +26,7 @@ To install from Maven:
 <dependency>
     <groupId>io.innerloop</groupId>
     <artifactId>java-neo4j-client</artifactId>
-    <version>0.3.0</version>
+    <version>0.4.0</version>
 </dependency>
 ```