Update pom.xml

The project doesn't build. com.zaxxer.HikariCP:2.1.1-SNAPSHOT is not available in public maven repository. Use the latest release version

 <dependency>
            <groupId>com.zaxxer</groupId>
            <artifactId>HikariCP</artifactId>
            <version>2.2.5</version>   ->   <version>2.2.5</version> 
 </dependency>