This a brew tap repository containing a "formulae" for airport-bssid.
First, add this tap to your Brew. This will clone this tap repository and symlink this formulae.
brew tap mehdichaouch/airport-bssid
Now you will be able to work on this formulae as if there were in canonical Homebrew repository:
For stable release
brew install airport-bssid
For latest non-stable from GitHub
brew install --HEAD airport-bssid