### Added
- MessagePack serialization for traces sent to the Agent with a new function `dd_trace_serialize_msgpack()` #378
### Changed
- Request init hook module blacklist now avoids miss matching partial matches #372
- Add 10MB cap to payloads sent to the Agent #388
- Added an `getTracesAsArray()` method to `DDTrace/Contracts/Tracer` which returns an array of spans (which are also encoded as an array.) To encode an instance of `DDTrace\Contracts\Span` as an array, use `DDTrace/Encoders/SpanEncoder::encode($span)` #378
- `DDTrace/Transport::send()` now takes an instance of `DDTrace/Contracts/Tracer` instead of an `array` #378
- `DDTrace/Encoder::encodeTraces()` now takes an instance of `DDTrace/Contracts/Tracer` instead of an `array` #378
- The default encoder is now `DDTrace/Encoders/MessagePack`. You can still use the JSON encoder by setting the environment variable `DD_TRACE_ENCODER=json`. It is generally not recommended to use the JSON encoder as parsing JSON payloads at the Agent level is more CPU & memory intensive.