I have a feeling `hostname` is not quite reliable.

At least on Virtualbox it didn't make my changes permanent.
Optional requirements not that optional.

While one may choose not to use homebrew, using it requires following
steps to be done first or running chef with sudo. I'd rather do first
so brew and caskroom dirs are created with correct permissions.
Homebrew also requires command line tools.
Command Line Tools would be also installed software updates.

Since it's recommended software update, and it's good idea to install
other recommended updates on fresh machine this is what's ordered.