[Travis] Run tests on PHP 7.1 (#3913)
[Travis] Run tests on PHP 7.1 (#3913)

* [Travis] Run tests on PHP 7.1
* [Travis] Don't test Phalcon on PHP 7.1
* [Travis] Don't enable mongo.so on PHP 7.1
Codeception/base,tasselchof/Codeception,pitpit/Codeception,Vreasy/Codeception,Codeception/base,kt81/Codeception,pitpit/Codeception,janhenkgerritsen/Codeception,Codeception/Codeception,janhenkgerritsen/Codeception,kt81/Codeception,tasselchof/Codeception,Codeception/base,sergeyklay/Codeception,Naktibalda/Codeception,Codeception/Codeception,Naktibalda/Codeception,tiger-seo/Codeception,tasselchof/Codeception,sergeyklay/Codeception,Naktibalda/Codeception,Vreasy/Codeception,tiger-seo/Codeception