extend java vm memory parameter in pom.xml

<project>
  [...]
  <build>
    [...]
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.1</version>
        <configuration>
          <fork>true</fork>
          <meminitial>512m</meminitial>
          <maxmem>1048m</maxmem>
        </configuration>
      </plugin>
    </plugins>
    [...]
  </build>
  [...]
</project>