text: Title: Messagebus send isn't working
  Body: ## Software:
  * Picroft
  * 19.2.13
  
  ## Problem
  
  This used to work before, but I've seen some work with refactoring the messagebus code, and that probably broke it.
  
  This is basically my code:
  ```python
  from mycroft.messagebus.send import send
  send("skill.communications.device.new", {"message": "10.0.1.7"})
  ```
  Which sends the message `skill.communications.device.new` from the code in my (communications) skill which handles new devices, to the Mycroft skill, to be registered.
  
  Now it is failing with the error:
  ```python-traceback
  Traceback (most recent call last):
    File "/usr/lib/python3.5/threading.py", line 914, in _bootstrap_inner
      self.run()
    File "/home/pi/mycroft-core/.venv/lib/python3.5/site-packages/zeroconf.py", line 1423, in run
      handler(self.zc)
    File "/home/pi/mycroft-core/.venv/lib/python3.5/site-packages/zeroconf.py", line 1363, in <lambda>
      zeroconf=zeroconf, service_type=self.type, name=name, state_change=state_change
    File "/home/pi/mycroft-core/.venv/lib/python3.5/site-packages/zeroconf.py", line 1250, in fire
      h(**kwargs)
    File "/home/pi/mycroft-core/.venv/lib/python3.5/site-packages/zeroconf.py", line 1335, in on_change
      listener.add_service(*args)
    File "/opt/mycroft/skills/communications-skill.linuss1/shippingHandling.py", line 107, in add_service
      send_communication_to_messagebus("device", ip)
    File "/opt/mycroft/skills/communications-skill.linuss1/shippingHandling.py", line 26, in send_communication_to_messagebus
      send("skill.communications.{}.new".format(msg_type), {"message": "{}".format(str(msg))})
    File "/home/pi/mycroft-core/mycroft/messagebus/send.py", line 70, in send
      url = MessageBusClient.build_url(
  AttributeError: type object 'MessageBusClient' has no attribute 'build_url'
  ```