Here are some brew commands to update your macosx php version to 7.1, including curl and mcrypt.
If you haven't brew installed on your local machine, feel free to do so with
/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
Copy and paste that snippet in your Terminal and the script will guide you through the installation process.
You can get more info for the installation process here: brew.sh
If you have brew installed, follow the commands provided in the brew_php71_macosx.sh file to install php 7.1 on your machine.
Or type in the following:
brew tap homebrew/dupes
brew tap homebrew/versions
brew tap homebrew/homebrew-php
brew install --with-openssl curl
brew install --with-homebrew-curl --with-apache php71
brew install php71-mcrypt php71-imagick
brew info php71
sudo apachectl restart
source ~/.profile
If you check your php version with php -v in your terminal and it still shows the old version, type in
export PATH=/usr/local/php5/bin:$PATH
The PATH settings should then update to the proper version.