Allow random_compat v9.99.99 on PHP 7 projects.
Allow random_compat v9.99.99 on PHP 7 projects.

For PHP 7+ software, we have a special tag at `v9.99.99` which is essentially empty. The purpose of this tag is to allow it to be loaded by Composer for PHP 7 software, and then not create conflicting definitions for static analysis tools and/or IDEs' type hinting.

See https://twitter.com/CiPHPerCoder/status/1004230888169852928
defuse/php-encryption,defuse/php-encryption