Update to use the official API (api.switch-bot.com)

[markszabo]

@OpenWonderLabs recently released their API documentation: https://github.com/OpenWonderLabs/SwitchBotAPI

Do you think it would make sense to update this library to use that?

One difference is authentication: the API docs recommends generating a token, and using that in the Authorization header. This seems like the same token this library generates with cognito though, so it is not necessarily a major change.

[jonghwanhyeon]

Close the issue because I updated to use the official API 👍