Homebrew explicitly discourages the use of sudo

Homebrew [explicitly discourages the use of sudo](https://github.com/Homebrew/homebrew/blob/master/share/doc/homebrew/FAQ.md#sudo) (emphasis mine):

> Homebrew is designed to work without using sudo. You can decide to use it but we strongly recommend not to do so. If you have used sudo and run into a bug then it is likely to be the cause. Please **don’t file a bug report unless you can reproduce it after reinstalling Homebrew from scratch without using sudo**.

With the current instructions a Homebrew saltstack install will not be supported by the Homebrew community.