Allow setting min/max SSL version for a Net::HTTP connection on Ruby 2.5

[bdewater]

The functionality in the OpenSSL gem was introduced in ruby/openssl#142 and supported by Net::HTTP in Ruby 2.5: ruby/ruby@dcea919

An example why this might be useful; for payment data the PCI DSS mandates that TLS 1.1 or newer is used after June 30. Using ssl_version would disallow the client negotiating TLS 1.2 (or 1.3 in the near future) if both sides support it, min_version doesn't have this problem.

[iMacTia]

Hi @bdewater, this makes sense, but unfortunately it won't work unless you add the new fields to the SSLOptions class.
Travis is in fact failing with the error: NameError: no member 'min_version' in struct

[bdewater]

Hey @iMacTia thanks for the pointer, I didn't have the time to dig into it yesterday but CI is green now 😄