Add rabbitmq-client in opennaas.
Merge branch 'develop' of https://github.com/dana-i2cat/opennaas into feature/rabbit-mq
SLAManager observation pusher client.

Allows pushing observations to SLAManager using rabbitMQ.

RabbitMQ info:
- API JavaDoc: http://www.rabbitmq.com/releases/rabbitmq-java-client/v3.2.4/rabbitmq-java-client-javadoc-3.2.4/
- API guide: http://www.rabbitmq.com/api-guide.html

WARNING: Untested. There is no server to test with.
Merge branch 'develop' of https://github.com/dana-i2cat/opennaas into rabbit-mq

Conflicts:
	pom.xml
Merge pull request #3 from adrian-rosello/rabbit-mq

Merge rabbit-mq branch with develop
Merge pull request #882 from isartcanyameres/feature/rabbit-mq

RabbitMQ

Client to send observations to SLAManager.

The client uses a rabbitMQ java client to communicate with the rabbitMQ broker where SLAManager is listening to.