See https://builds.apache.org/job/maven-box/job/maven-source-plugin/job/MSOURCES-95/21/
Changes: * Use Maven 3.6.3 for Linux builds, it should already be on all nodes * Use Java 8 for Java 7 builds - due to the temporary removal of Java 7 * JDK 1.7.0_80 added back in All tests passed
