Installation on Mac

Instead of using PHPenv, ended up going with advice from here: https://stackoverflow.com/questions/69555525/error-while-doing-brew-tap-exolnet-homebrew-deprecated

And here: https://www.markhesketh.com/switching-multiple-php-versions-on-macos/

brew tap shivammathur/php
brew install php@5.6 # For old projects
# Switching:
brew unlink php@7.4
brew link php@5.6 --force