Description:
------------
---
From manual page: http://www.php.net/sqlite3.construct
---
https://github.com/php/php-src/commit/cc125f277b50e0f90fc8033fe7f47d2446389a15

According to this commit, the filename in the constructor may also be an empty string since v7.0.10. This will result in a in-memory database. In previous versions of PHP7 (I tested this with v7.0.2) this would have resulted in a exception. 

The documentation is not mentioning this feature. 

Test script:
---------------
The unit test below works in v7.0.2, but fails in v7.0.17

class SQLiteConstructorTest extends PHPUnit_Framework_TestCase
{
    /**
     * @expectedException Exception
     */
    public function testDefectDatabaseFile()
    {
        $database_file = '';
        $sqlitedb = new SQLite3($database_file);
    }
}