Check if `brew` is installed every time, and *unset* `$BASH_IT_HOMEBREW_PREFIX` if not found. This accounts for the edge-case of a user _uninstalling_ Homebrew without restarting the shell.
Check if `brew` is installed every time, and *unset* `$BASH_IT_HOMEBREW_PREFIX` if not found. This accounts for the edge-case of a user _uninstalling_ Homebrew without restarting the shell.