cli_common: Add hg robustcheckout helper (#284)
cli_common: Add hg robustcheckout helper (#284)

lundjordan/services,La0/mozilla-relengapi,srfraser/services,garbas/mozilla-releng-services,mozilla-releng/services,mozilla-releng/services,garbas/mozilla-releng-services,lundjordan/services,mozilla-releng/services,La0/mozilla-relengapi,garbas/mozilla-releng-services,lundjordan/services,lundjordan/services,La0/mozilla-relengapi,srfraser/services,mozilla-releng/services,srfraser/services,La0/mozilla-relengapi,garbas/mozilla-releng-services,srfraser/services