move unittests
add config arg to BusConsumer init
add virtual_host into bus config
add config arg to BusProducer init
move amqp_transport_client module to rpc package
move BusCtlServerError exception
move BusProducerError exception
update BusConfig
Fix unittest that failed following the rename of Config

fixes commit 0fd42c2e7484c24a0d47759c1a75dc1de7eab071
Merge pull request #9 from xivo-pbx/refactor_bus_interface

Refactor bus interface