Author: Ryan Wyllie
MDL-50624 environment: add PHP7 as unsupported version
Added PHP7 as an unsupported version for Moodle 2.7, 2.8 and 2.9
in the environment checks
http://git.moodle.org/gw?p=moodle.git;a=commit;h=81d961ba3a719051aba38c2ef3c4f81d56a3c876
http://github.com/moodle/moodle/commit/81d961ba3a719051aba38c2ef3c4f81d56a3c876
+ 2.7 en [unsupportedphpversion7,core_admin]