LEMP stack is not compatible with MariaDB. Should it be?

[ocdtrekkie]

So the primary issue with #220 appears to have been that Debian Stretch decided to drop in MariaDB 10.1 as a replacement for MySQL 5.5. I am going to proceed with the "get things working first" strategy, and grab MySQL by adding a different apt source for it.

Debian clearly believes MariaDB is a superior drop-in replacement for MySQL to the tune of it installing it when you call apt-get install mysql-server, but the configuration changes we make in setup.sh do not work on MariaDB 10.1, particularly with regards to telling it not to use the mysql user account.

Are there improvements MariaDB makes that will benefit the Sandstorm stack to prefer? If so, how do we fix vagrant-spk to work with MariaDB? And are there any significant compatibility issues people expecting a PHP/MySQL stack will have if we do so?