Automatically setup an upstream remote

upstream

#!/usr/bin/env groovy

import groovy.json.JsonSlurper

def (_, owner, repo) = ('git remote get-url origin'.execute().text =~ /\/([^\/]+)\/([^\/]+)$/)[0]
def parentUrl = new JsonSlurper().parse(new URL("https://api.github.com/repos/$owner/$repo")).parent.html_url

"git remote add upstream $parentUrl".execute()