Remove outdated local JSON Schemas

[farshidtz]

https://github.com/TinyIoT/thing-directory/blob/8fca01e7913868ce13619613e5658705c25d861b/wot/discovery_schema.json
https://github.com/TinyIoT/thing-directory/blob/8fca01e7913868ce13619613e5658705c25d861b/wot/wot_td_schema.json

The latest versions can be downloaded:
https://github.com/TinyIoT/thing-directory/wiki/Configuration#validation