Gradle optional dependencies

release.gradle

def installer = install.repositories.mavenInstaller
def deployer = uploadArchives.repositories.mavenDeployer

[installer, deployer]*.pom*.whenConfigured {pom ->
    def dependencyMap = project.configurations.compile.dependencies.collectEntries { [it.name, it] }
    pom.dependencies.findAll {
        def dep = dependencyMap[it.artifactId]
        return dep?.hasProperty('optional') && dep.optional
    }*.optional = true
}