With this commit the support for Turbine is completly revised. From now
on Turbine is supported via a separate module and is integrated as top
level view.

closes #306

In case a hystrix.stream does'nt sends any data and just a ping the endpoint is
not detecet correctly and the ui get unresponsive. The problem is that the sent
"ping:" chunk doesn't triggers the message event listener.
So instead we use a simple HEAD-request to get the header and status.

fixes #276

By using the netflix/hystrix-dashboard this module allows you to view the
metrics from hystrix/turbine in the spring boot admin server. This module needs
to be added explicitly.

closes #147