Queuing service

[lutzmor]

Implement queue service, initially using https://github.com/Automattic/kue

Create an injectable Queue service, that has all common methods and a KueQueue implementation, to allow for more hot-swappable (even at runtime) drivers in the future, like AmazonSQS, RabbitMQ, Beanstalkd, IronIO etc.

This is a good candidate component for working out how to do separate components that add items to the docker-compose configuration (it should have it's own instance of a redis server). Consider building this as a completely separate repository to work out how to do component modularity properly.