add  <jdk>[1.8,)</jdk> in your pom file to override doc.

	</plugins>
	</build>
	<profiles>
		<profile>
			<id>doclint-java8-disable</id>
			<activation>
				<jdk>[1.8,)</jdk>
			</activation>
		</profile>
	</profiles>
</project>

or add following to your pom.xml

<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.2.4</version>
</dependency>