Update Java required version in a plugin project / webengine project to java 8

*In the pom.xml file*

Current configuration is:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>

It should be 1.8 instead.

*In the manifest.mf file*

Current configuration is:
Bundle-RequiredExecutionEnvironment: JavaSE-1.7

It should be 1.8 instead.