rough cut liftoff integration

Opening this for discussion--the implementation isn't complete.  Liftoff currently doesn't support keying off completely separate configuration files, just one configuration file with varying extensions.  Are you committed to supporting the `package.json` config option?  If yes, I'll have to make some updates to Liftoff.  

In either case, please have a look at this and let me know how you feel about the direction I'm taking things?  I think it makes sense to load the configuration in the cli and pass it directly to the runner.