Pulsar-queue

Obfuscate consumer urls

Several internal changes and bug fixes
- Dropped `pubsub` in favour of pulsar `channels`
- Redis backend uses namespace for both channels and queues
- Better serialisation support for messages
- Added `register_broker` function to api
- Added `queue_message` function to api

Backward incompatible release with a considerable amount of internal and API refactoring
- Ability to add additional consumers to the queue server (see [pulsar-twitter](https://github.com/quantmind/pulsar-twitter) for example)
- Each consumer is an attribute of the server queue api and backend objects
- Renamed `TaskFuture` to `MessageFuture`
- Handle `max_retries` with `retry_delay`
- `TaskError` can be used in order to avoid a full stack trace dump. It means it is a TaskError handled by the Job callable.
- Added `timeout` to task execution
- Max concurrent tasks is a linear function of number of cores and `concurrent_tasks` parameter

Several backward incompatible changes. This version is not compatible with the 0.3 series
and brings several bug fixes, enhancements and almost 100% test coverage.
- Added `TaskManager` for better customise the task queue application
- Added message serialisers - `json` and `msgpack`
- Consumers can run on a single process [b392f82](https://github.com/quantmind/pulsar-queue/commit/b392f826a2544032a7775bfcfceb4ce2d89fd3ba)
- Allow to queue tasks with a delay [3ed7d7a](https://github.com/quantmind/pulsar-queue/commit/3ed7d7a4795bea0a8071201e5506ac4b6d1089ed)
- Handle drop connections from pubsub and message queue broker
- Enhanced documentation

- Increased code coverage
- Fixed RPC server
- Increased documentation
- Bug and API fixes

- Major code refactoring with introduction of submodules
- Task queue Backend has Pubsub and Message queue handlers