[ERROR] Failed to execute goal org.apache.maven.plugins:maven-checkstyle-plugin:2.15:check (default) on project magnolia-ui-project: Execution default of goal org.apache.maven.plugins:maven-checkstyle-plugin:2.15:check failed: Plugin org.apache.maven.plugins:maven-checkstyle-plugin:2.15 or one of its dependencies could not be resolved: Could not find artifact com.sun:tools:jar:1.6.0 at specified path /Library/Java/JavaVirtualMachines/jdk-9.0.4.jdk/Contents/Home/../lib/tools.jar -> [Help 1]