cmd/juju/commands: refactor bootstrap_test
cmd/juju/commands: refactor bootstrap_test

Clean up bootstrap test a little to make it easier to merge my mega
change later.

ericsnowcurrently/juju,ericsnowcurrently/juju,howbazaar/juju,kat-co/juju,fwereade/juju,mjs/juju,axw/juju,kat-co/juju,waigani/juju,dooferlad/juju,mjs/juju,davecheney/juju,bogdanteleaga/juju,bz2/juju,davecheney/juju,fwereade/juju,frankban/juju,axw/juju,bz2/juju,perrito666/juju,frankban/juju,bogdanteleaga/juju,howbazaar/juju,perrito666/juju,kat-co/juju,wwitzel3/juju,marcmolla/juju,mjs/juju,bac/juju,gabriel-samfira/juju,davecheney/juju,anastasiamac/juju,kat-co/juju,reedobrien/juju,mikemccracken/juju,dooferlad/juju,dimitern/juju,dooferlad/juju,bac/juju,howbazaar/juju,reedobrien/juju,bogdanteleaga/juju,AdamIsrael/juju,waigani/juju,macgreagoir/juju,mjs/juju,fwereade/juju,macgreagoir/juju,bac/juju,waigani/juju,mikemccracken/juju,bz2/juju,anastasiamac/juju,reedobrien/juju,reedobrien/juju,perrito666/juju,ericsnowcurrently/juju,wwitzel3/juju,anastasiamac/juju,voidspace/juju,marcmolla/juju,dimitern/juju,axw/juju,frankban/juju,axw/juju,voidspace/juju,makyo/juju,bogdanteleaga/juju,makyo/juju,voidspace/juju,howbazaar/juju,frankban/juju,dooferlad/juju,alesstimec/juju,alesstimec/juju,macgreagoir/juju,frankban/juju,alesstimec/juju,AdamIsrael/juju,mikemccracken/juju,gabriel-samfira/juju,perrito666/juju,dimitern/juju,mikemccracken/juju,axw/juju,anastasiamac/juju,alesstimec/juju,mjs/juju,AdamIsrael/juju,AdamIsrael/juju,howbazaar/juju,kat-co/juju,ericsnowcurrently/juju,makyo/juju,davecheney/juju,bz2/juju,gabriel-samfira/juju,marcmolla/juju,gabriel-samfira/juju,wwitzel3/juju,mjs/juju,ericsnowcurrently/juju,makyo/juju,alesstimec/juju,perrito666/juju,mikemccracken/juju,fwereade/juju,macgreagoir/juju,reedobrien/juju,anastasiamac/juju,bac/juju,dimitern/juju,marcmolla/juju,mjs/juju,bz2/juju,bac/juju,voidspace/juju,marcmolla/juju,macgreagoir/juju,wwitzel3/juju,dooferlad/juju,waigani/juju,dimitern/juju,gabriel-samfira/juju