feat(core_upload_update): use flag parsing library
feat(core_upload_update): use flag parsing library

convert to use the flag parsing library instead of lots of positional
args.

andrejro/coreos--scripts,bcwaldon/coreos-scripts,marineam/coreos-scripts,vmware/coreos-scripts,coreos/scripts,gtank/scripts,nicescale/scripts,sigma/coreos-scripts,fivethreeo/scripts,smilart/scripts,vmware/coreos-scripts,endocode/scripts,endocode/scripts,glevand/coreos--scripts,crawford/scripts,zhang0137/scripts,nicescale/scripts,mjg59/scripts,fivethreeo/scripts,mischief/scripts,andrejro/coreos--scripts,trnubo/scripts,trnubo/scripts,vmware/coreos-scripts,BugRoger/scripts,trnubo/scripts,bcwaldon/coreos-scripts,BugRoger/scripts,mjg59/scripts,coreos/scripts,crawford/scripts,marineam/coreos-scripts,sigma/coreos-scripts,glevand/coreos--scripts,mischief/scripts,fivethreeo/scripts,mischief/scripts,sigma/coreos-scripts,marineam/coreos-scripts,BugRoger/scripts,gtank/scripts,nicescale/scripts,bcwaldon/coreos-scripts,zhang0137/scripts,smilart/scripts,endocode/scripts,crawford/scripts,smilart/scripts,andrejro/coreos--scripts,zhang0137/scripts,mjg59/scripts,gtank/scripts