Remove SslHttpClient?

I would like to remove this class and all the code (constructors in ``RemoteDocker``, mostly) that makes any assumption regarding securing communication with a remote Docker instance.

My reasoning is that we shouldn't make any assumptions since we will most likely not cover all the possibilities and we are just polluting the library. If the user really needs it and knows what they are doing, they can provide a properly configured ``HttpClient`` when instantiating a ``RemoteDocker``.

What do you think?

Start by locating SslHttpClient and the constructors in RemoteDocker, then trace how they assume secure communication with a remote Docker instance. Review the comment discussion before deciding the scope. Done means those assumptions and related code are removed while callers can provide a configured HttpClient.

Written by the indexing model from the issue text.