scala-cross-build-maven-plugin provides goals that help maintaining Scala cross version builds with Maven.
See src/it/full-example/pom.xml for an example.
# Change Scala version in pom.xml.
mvn scala-cross-build:change-version -Pscala-2.11
# Transform JUnit XML reports to append Scala binary version to test case names.
mvn scala-cross-build:transform-junit-reports -Pscala-2.11
# Change back to the default Scala version.
mvn scala-cross-build:restore-version