Installing CiviCRM 4.7 in Drupal 7 can't match requirements
The real issue is that your database credentials are invalid.

Access denied for user 'civicrm'@'localhost' (using password: NO)

Access denied for user 'drupal'@'localhost' (using password: NO)

Most likely the warning you are seeing is due to the connection object being FALSE as a result of not being able to connect, instead of a mysqli connection object.

The database: 'drupal' does not exist.

You should also at the very least create the drupal and civicrm databases you intend to use; Drupal and CiviCRM's installation will create all the necessary tables.