PHP 7.1 is not pre-installed in CircleCI’s Ubuntu 14.04 image, yet.
In the meantime, here’s how you can use PHP 7.1 on CircleCI (Ubuntu 14.04) in the same way you would other supported PHP versions:
machine:
pre:
- sudo apt-get update; USE_PRECOMPILE=true sudo -E circleci-install php 7.1.0
php:
version: 7.1.0
test:
override:
- php --version