If the database isn't found when checking for the connection it means, we can connect to the server.
The InstallCommand will create the database later.
Also, when checking for the SQLite connection, Doctrine creates the file (so the database). That's why the test is skipped for SQLite.
Ensure tests after the InstallCommand test will have a clean database.
Previous attempt failed because of a foreign key
Also, nightly on Travis seems to target PHP 7.2-dev, so I put 7.1 in requirement and moved nightly in allowed failures.
And it seems xdebug isn't shipped with PHP 7.1, so I added a workaround to avoid build to fail when trying to remove xdebug.ini file.
