Apply license header to `package-info.java` and `module-info.java`

We added spotless with the Google Java style:

spotless {
java {
googleJavaFormat("1.7")
licenseHeaderFile "${project.rootDir}/company.license.java"
}
}

and it formatted all code...but left all the **package-info.java** classes untouched when we run spotlessJavaApply

is that expected behaviour or a bug? How can we force the format to include those files as well?