Prevent dir walking when searching for a project

[andscoop]

This ended up being more re-work than expected as projectRoot was always looking in the curr dir and walking upwards towards usr root dir if config not found. All walking of dirs has been removed in favor of commands that need a config being run directly out of a project root.

• closes Astro init looks at parent directory #103
• adds prompt on astro init if user is in non-empty directory
• removes the upward walking of a dir if user is not in an immediate project dir (defined by existence of config)

[schnie]

Makes sense, sounds good to me.