source 6 no longer works, please upgrade to source 7 code example
Example: maven source option 5 is no longer supported use 7 or later
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>