COOPR-621 Do not require Internet for chef-solo bootstrap

Here's the flow:

yum -> apt -> curl -> wget -> FAIL

This should allow organizations to provide the `chef` package via their own YUM/APT repositories, which may reside inside their firewall.
I agree. However, I feel that should be a refactor across everywhere that it's used (fog_provider, shell_automator, too) rather than just a change here.