I've a new server with PHP
v7.1.0RC3 installed. According to DevDocs Magento 2 is compatible with
7.0.2 up to 7.1.0, except for 7.0.5 which makes
PHP 7.1.0 compatible with M2 however when tried to install repo I get following error:
Problem 1 - Installation request for magento/product-community-edition 2.1.1 -> satisfiable by magento/product-community-edition[2.1.1]. - magento/product-community-edition 2.1.1 requires php ~5.6.0|7.0.2|~7.0.6 -> your PHP version (7.1.0RC3) does not satisfy that requirement.