AddPHP7.1asoptionalonTravis

| Questions | Answers
| ------------- | -------------------------------------------------------
| Branch? | develop
| Description? | PHP 7.1 is now available from a few months. It's time to include it in the tests matrix. Eventually, it can replace PHP 7.0.
| Type? | improvement
| Category? | TE
| BC breaks? | Nope
| Deprecations? | Nope
| Fixed ticket? | /
| How to test? |

该提问来源于开源项目：PrestaShop/PrestaShop