Revise spec test for state of change stream cursor
Revise spec test for state of change stream cursor

The spec requests that we check that the initial change stream cursor is alive. This can be done by both asserting its cursor ID is non-zero and also calling MongoDB\Driver\Cursor::isDead().

jmikola/mongo-php-library,derickr/mongo-php-library,mongodb/mongo-php-library,jmikola/mongo-php-library,jmikola/mongo-php-library,derickr/mongo-php-library,mongodb/mongo-php-library,10gen-labs/mongo-php-library-prototype,mongodb-labs/mongo-php-library-prototype,jmikola/mongo-php-library-prototype,derickr/mongo-php-library-prototype,jmikola/mongo-php-library,mongodb/mongo-php-library,mongodb/mongo-php-library