Revert "Remove mrm-maven-plugin"

[basil]

Reverting #828, since I didn't notice in the original build that it introduced a bunch of new warnings:

13:48:22  [INFO] [INFO] Artifact org.apache.maven:maven-parent:pom:39 is present in the local repository, but cached from a remote repository ID that is unavailable in current build context, verifying that is downloadable from [central (https://repo.maven.apache.org/maven2, default, releases)]
13:48:22  [INFO] [INFO] Artifact org.apache.maven:maven-parent:pom:39 is present in the local repository, but cached from a remote repository ID that is unavailable in current build context, verifying that is downloadable from [central (https://repo.maven.apache.org/maven2, default, releases)]
13:48:22  [INFO] [INFO] Artifact org.apache:apache:pom:29 is present in the local repository, but cached from a remote repository ID that is unavailable in current build context, verifying that is downloadable from [central (https://repo.maven.apache.org/maven2, default, releases)]
13:48:22  [INFO] [INFO] Artifact org.apache:apache:pom:29 is present in the local repository, but cached from a remote repository ID that is unavailable in current build context, verifying that is downloadable from [central (https://repo.maven.apache.org/maven2, default, releases)]
13:48:22  [INFO] [INFO] Artifact org.codehaus.plexus:plexus-utils:pom:3.4.2 is present in the local repository, but cached from a remote repository ID that is unavailable in current build context, verifying that is downloadable from [central (https://repo.maven.apache.org/maven2, default, releases)]
13:48:22  [INFO] [INFO] Artifact org.codehaus.plexus:plexus-utils:pom:3.4.2 is present in the local repository, but cached from a remote repository ID that is unavailable in current build context, verifying that is downloadable from [central (https://repo.maven.apache.org/maven2, default, releases)]