Test interface and simulation for users without hardware

[refugeesus]

As a user I want to be able to test the Helium router and cloud channel integrations without having to buy hardware initially.

To solve this I suggest exposing an interface to the dashboard and channels as "virtual atoms" and "virtual gateways" which can interface with a standard channel and any cloud service through it. The virtual atoms can be transmitting data via some MQTT pub/sub or REST style API (or something else?) to simulate an atom sending data end-to-end.

Additional features of the virtual devices could be tools to introduce/adjust network jitter, interference, latency at different branches, etc..