When not specifiying a profile with the -p option, don't assume we can safely use one called 'profile'
When not specifiying a profile with the -p option, don't assume we can
safely use one called 'profile'

This borked CI which relies on IAM Instance Profiles, and has no AWS
CLI configuration to speak of

Fixes #106

tinnightcap/nubis-builder,limed/nubis-builder,gozer/nubis-builder,Nubisproject/nubis-builder