fatal error compiling: invalid flag: --release
In your pom.xml file, simply remove the tag <release>8</release> from your maven-compiler-plugin configuration:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.7.0</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<verbose>true</verbose>
</configuration>
</plugin>