Replace RabbitMQ with ActiveMQ

[sreejithcts]

In OpenOCR can we replace RabbitMQ with ActiveMQ which has Apache licensing.

[tleyden]

@sreejithcts I was originally going to say it sounds like a ton of work, but since the code uses github.com/streadway/amqp to talk to the message queue, it might be just a matter of swapping out the rabbitmq docker image with activemq.