Add ok check for interface{} --> string type assertion
Add ok check for interface{} --> string type assertion

dimitern/juju,marcoceppi/juju,tych0/juju,howbazaar/juju,sinzui/juju,reedobrien/juju,ericsnowcurrently/juju,cloud-green/juju,anastasiamac/juju,mikemccracken/juju,bz2/juju,frobware/juju,perrito666/juju,jrwren/juju,kat-co/juju,anastasiamac/juju,davecheney/juju,gabriel-samfira/juju,cloud-green/juju,ericsnowcurrently/juju,mjs/juju,macgreagoir/juju,dimitern/juju,tsakas/juju,AdamIsrael/juju,cmars/juju,cmars/juju,cherylj/juju,axw/juju,dimitern/juju,mhilton/juju-juju,mjs/juju,ericsnowcurrently/juju,mhilton/juju-juju,Altoros/juju-cloudsigma,mjs/juju,mikemccracken/juju,davecheney/juju,gabriel-samfira/juju,AdamIsrael/juju,mjs/juju,makyo/juju,perrito666/juju,ericsnowcurrently/juju,gabriel-samfira/juju,thomnico/juju,alesstimec/juju,cmars/juju,marcmolla/juju,Altoros/juju-vmware,alesstimec/juju,tych0/juju,cherylj/juju,mikemccracken/juju,bz2/juju,jrwren/juju,dooferlad/juju,bac/juju,davecheney/juju,alesstimec/juju,axw/juju,AdamIsrael/juju,anastasiamac/juju,voidspace/juju,mhilton/juju,thomnico/juju,anastasiamac/juju,macgreagoir/juju,tsakas/juju,reedobrien/juju,frankban/juju,AdamIsrael/juju,howbazaar/juju,tasdomas/juju,reedobrien/juju,frankban/juju,dimitern/juju,frankban/juju,voidspace/juju,tych0/juju,bz2/juju,frobware/juju,perrito666/juju,bac/juju,howbazaar/juju,sinzui/juju,howbazaar/juju,sinzui/juju,kat-co/juju,mjs/juju,bogdanteleaga/juju,tasdomas/juju,tasdomas/juju,bogdanteleaga/juju,waigani/juju,fwereade/juju,thomnico/juju,frankban/juju-tmp,waigani/juju,mjs/juju,dooferlad/juju,mhilton/juju-juju,axw/juju,makyo/juju,axw/juju,mhilton/juju,bz2/juju,alesstimec/juju,gabriel-samfira/juju,wwitzel3/juju,kat-co/juju,marcmolla/juju,fwereade/juju,bac/juju,mikemccracken/juju,voidspace/juju,perrito666/juju,makyo/juju,cloud-green/juju,wwitzel3/juju,cherylj/juju,wwitzel3/juju,sinzui/juju,cmars/juju,marcmolla/juju,frankban/juju-tmp,reedobrien/juju,dimitern/juju,cherylj/juju,tsakas/juju,bac/juju,bac/juju,Altoros/juju-cloudsigma,frankban/juju-tmp,frankban/juju,mhilton/juju,frankban/juju,wwitzel3/juju,cloud-green/juju,bz2/juju,waigani/juju,ericsnowcurrently/juju,macgreagoir/juju,bogdanteleaga/juju,makyo/juju,Altoros/juju-vmware,mhilton/juju,fwereade/juju,marcoceppi/juju,perrito666/juju,marcoceppi/juju,mhilton/juju-juju,macgreagoir/juju,marcmolla/juju,dooferlad/juju,dooferlad/juju,tasdomas/juju,reedobrien/juju,dooferlad/juju,voidspace/juju,Altoros/juju-vmware,tsakas/juju,tych0/juju,frobware/juju,Altoros/juju-vmware,fwereade/juju,anastasiamac/juju,kat-co/juju,thomnico/juju,frankban/juju-tmp,macgreagoir/juju,marcmolla/juju,mikemccracken/juju,howbazaar/juju,jrwren/juju,gabriel-samfira/juju,davecheney/juju,bogdanteleaga/juju,Altoros/juju-cloudsigma,waigani/juju,marcoceppi/juju,mjs/juju,Altoros/juju-cloudsigma,alesstimec/juju,kat-co/juju,axw/juju