PHP Version to >= 7.1

[cdgco]

In order to continue effectively developing and efficiently testing updates as well as maintaining security, minimum PHP version should be increased to 7.1, which aligns with requirements for Motranslator and Auth0.

However, the most common PHP version installed on VWI systems this year was PHP 7.0. Although there were more total installations with PHP 7.1+, there is still a large number of users who would have to upgrade.

If you have any input on whether I should update the requirement or continue developing for PHP 5.4+ or PHP 7.0+ let me know by commenting below.