Test amqp

[frederike-ramin]

Currently there are no tests for amqp.

Can be implemented via Dependency Injection.

[cmfcmf]

Can be implemented via Dependency Injection.

To give some more context, the AmqpConnector should be refactored to receive the amqplib instance during construction. This allows a test to supply a fake amqplib instance which doesn't communicate to any real amqp service, but rather spies on the invoked methods and asserts that certain methods have been called. The Mocha docs have a list of supported spying libraries.