Are you serious? 
You are a member here in this very forum for over two years (so I assume, you use HA for at least these two years) and you haven't noticed this message before? Is this your only custom_component you installed?
Nevermind, the warning (not error) message tells you exactly what is happening. You are using a custom_component that is not tested by the HA core development team. That's all. Like it says...
And btw. it would be good, if you could take a look at the rules for just a moment (especially the part about formatting), you could find them here: