Add `pause_consumer!` helper
Add `pause_consumer!` helper

This helper can be placed on top of the file to pause the consumer from
consuming the event on the queue. The queue and the routing of the
message will still be created as if this is a live consumer.

Usage:

    class SomeConsumer
      include Streamy::Consumer
      pause_consumer!
    end

cookpad/streamy,cookpad/streamy