Automatically determine :ssl based on connection uri

[reify-james-vickers]

protojure.grpc.client.providers.http2/connect takes a map that must contain :uri and can optionally contain :ssl with boolean value. It seems possible to automatically know that SSL should be used if the uri starts with https:// which is defining the connection scheme as HTTPS/SSL. Would it be possible to not have to provide :ssl in such cases then?

[ghaskins]

Yes, definitely possible. The ssl field should remain for backwards compat, but we could make it have a default based on the scheme. I would consider a PR that implements this.

[reify-james-vickers]

#136