Bringing back Cert Security Scheme

[egekorkan]

In the CR transition for v1.0, we still had the Cert Security Scheme (https://www.w3.org/TR/2019/CR-wot-thing-description-20191106/#certsecurityscheme). However, due to lack of implementation we had removed it. However, the implementation for the sayWoT! had started before the removal of this and it had this security scheme implemented. Since it was not submitted to the implementations of v1.0, this security scheme was removed.

When I was submitting for the v1.1, I had validation errors since our schema does not allow for unknown security schemes at the moment. I have talked with the developers and they do have the interest on bringing this back into the standard.

@mmccool What do you think? Do we still have time?

[egekorkan]

Call of 20.04:

• We will not try to reintroduce it this late.
• With TD2.0 , we want to tackle security differently anyways so introducing this would be a temporary solution and not worth it at the moment.

[egekorkan]

I have also learned from @thjaeckle that for MQTT, Cert Security Scheme is very common