This also removes "--prefer-source", which should result in Composer downloading dist releases by default.

Disable the "mongodb" service and remove installation through Travis' unmaintained apt package whitelist. Server versions are now manually downloaded and run with mongo-orchestration.

Since maxAwaitTimeMS is not a hard limit (the server may reply sooner), this will help avoid fragile test failures.

Thank you, PedantryTest.

The resume callable does not change, so we can create it once from the Manager provided to Watch's constructor.

UnexpectedValueException is only relevant for non-cursor aggregations, and UnsupportedException due to a write concern is not relevant for change streams.

Previously, Watch did not validate the "fullDocument" option and neglected to pass "readConcern" and "readPreference" to Aggregate. This refactors the class so that Watch only processes its own options.

Additionally, Aggregate is now first created from Watch::__construct() instead of Watch::execute(), which allows its options to be validated earlier (akin to FindOne creating Find in its constructor). Aggregate is only recreated if a new resume token is provided during a resume.

Read concern is supported by all server versions that support change streams, so we need not discuss its requirement.

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().

Previously, iteration started with next(), so the first element's key was 1. Iteration should being with rewind() and the initial key should be zero.

With this change, we're still testing that the key is only incremented when next() successfully increments.

Resume tests for rewind() will be reimplemented in PHPLIB-322

This also adds more assertions between the doc examples.