Fix Twitter API endpoint to use HTTPS; improve logging

I'm surprised this worked before, but updating tweets via the Twitter API now requires SSL.

[Details](https://dev.twitter.com/docs/auth/application-only-auth):

> SSL absolutely required
> 
> This manner of authentication is only secure if SSL is used. Therefore, all requests (both to obtain and use the tokens) must use HTTPS endpoints, which is also a requirement of using API v1.1.