Switch from PHP 5.6 to 7.1 (task #7636)
Switch from PHP 5.6 to 7.1 (task #7636)

* Updated to new plugin versions that drop support for PHP 5.6
  and PHP 7.0.
* Locked PHPUnit to v6 until CakePHP 3.6 upgrade.

QoboLtd/project-template-cakephp,QoboLtd/project-template-cakephp,QoboLtd/project-template-cakephp,QoboLtd/project-template-cakephp,QoboLtd/project-template-cakephp