Null check around Hubs
We are seeing the following error come from this 
`java.lang.NullPointerException: Cannot get property 'localIP' on null object`

I believe it's from here, if a location has no hubs. This scenario should be handled more gracefully. 

https://github.com/pdlove/homebridge-smartthings/blob/master/smartapps/pdlove/json-complete-api.src/json-complete-api.groovy#L174