An updated driver compatible with both PHP 7.0 and Linux is available on the PHP-7.0-Linux branch of https://github.com/Microsoft/msphpsql/
This is more up to date and supports some additional features over the ODBC / DBLIB drivers.
It is currently considered an 'Early Technical Preview' and hence has some limitations, but in my experience it has been stable.