Failed to construct CustomElement when we create w-radio dynamically

[cwpeng]

How to get this bug:

1. Go to our website: https://padax.github.io/w-components/
2. Open console and execute code: document.createElement("w-radio");
3. We can get error message as below:
   

If we google error message, I get this discussion from stackoverflow:
https://stackoverflow.com/questions/43836886/failed-to-construct-customelement-error-when-javascript-file-is-placed-in-head