COOK-2145 - Perform steps from mysql_secure_installation

Documented allow_remote_root in the READNE.md and updated the grants.sql to delete non-localhost root users if it is false. Also updated to use the queries that mysql_secure_installation uses which updates all root passwords instead of just the localhost one.

Added remove_anonymous_users (default false) which deletes users with no username for security, again copying the query from mysql_secure_installation and documenting in the README.md

Added remove_test_database (default false) which deletes the test database that should not exist in production. It also removes any privliges to the test DB or DBs starting with test_ . These queries are also copied from mysql_secure_installation and documented in the README.md