PHP 7.1 Upgrade Homebrew

To upgrade from PHP 7.0 to 7.1 on Homebrew you have to first inlink 7.0 and then install 7.1:

brew unlink php70
brew install php71

Then you can check the version running on your Mac using;

php -v
PHP 7.1.3 (cli) (built: Mar 28 2017 21:57:28) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies

NB It is recommended to do a:

brew update

and

brew upgrade

before you do all of the above. This so you have the latest Homebrew and formulas.