Added HTTPS and transport options support to Tornado transport

This adds HTTPS support for the Tornado transport. Tornado's `HTTPClient` and `AsyncHTTPClient` support HTTPS just fine, so enabling it was just a matter of adding the scheme to `TornadoTransport`.

I also added support for the 3 optional GET params, since tornado's interface allow them to be pretty much passthroughs to `fetch()`:

timeout => connect_timeout
verify_ssl => validate_cert
ca_certs => ca_certs

Also, tornado actually supports 2 types of timeouts. The other option is `request_timeout` which measures the time it takes the whole request to finish instead of `connect_timeout` which only measures the connection opening. I figured the intent of timeout was for connection timeout.