find artifact versions in nexus and sort

jenkins-nexus-artifact-versions.groovy

def url = '.../maven-metadata.xml'

def metadataText = "curl ${url}".execute().text
def parser = new XmlParser();
def xml = parser.parseText(metadataText);

def versions = []
xml.'**'.version.each { v -> 
  versions.add(v.text())
}

println versions.findAll{ v -> !v.contains('.') && v.startsWith('1') }.collect { v -> v as int }.sort().reverse()