Add fix for mysql_grant statement in CI
Add fix for mysql_grant statement in CI

This was failing since we upgraded the MySQL Puppet module. The user and
table needs to be seperated with a slash.

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet