Make faked AllocateMachine return constraint matches
Make faked AllocateMachine return constraint matches

Since maasEnviron.StartInstance calls instance.volumes, which now
requires some constraint matches to work.

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