RestClientBuilder SSL protocol should be configurable

Currently, RestClientBuilder defaults to TLS1.0 for underlying SSL protocol.  TLS1.0 is widely known to be insecure and susceptible to many CVE(s).  However, due to the fact that many production Servers still utilize this flawed protocol, it is still somewhat useful in a documented and otherwise secure context.

RestClientBuilder should at least contain a configuration option for underlying SSL protocol in order to allow future upgrade to a more secure protocol, and backwards compatibility with existing servers.