provider/ec2: increas root disk tagging timeout
provider/ec2: increas root disk tagging timeout

When we start instances in ec2, we tag the root disk
with the environment UUID, machine ID, etc. This will
sometimes fail if the root disk does not attach quickly
enough. Increase the timeout from 5 seconds to 5 minutes.

Fixes https://bugs.launchpad.net/juju-core/+bug/1501559

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