Force composer to require PHP Version between Version X and Version Y

Since the config parameter in composer.json is available. You could something like this:

{
    "name": ".../...",
    "config": {
        "platform": {
            "php": "5.3.5"
        }
    },
    "require": {
        ...
    }
} 

https://getcomposer.org/doc/06-config.md#platform