Add HTTPS Proxy support

net-http version 0.5.0 finally introduced TLS proxy support: ruby/net-http#55
https://github.com/ruby/net-http/releases/tag/v0.5.0

Author: richardmarbach

lib/faraday/adapter/net_http.rb

@@ -53,7 +53,8 @@ def net_http_connection(env)
         if proxy
           Net::HTTP.new(env[:url].hostname, port,
                         proxy[:uri].hostname, proxy[:uri].port,
-                        proxy[:user], proxy[:password])
+                        proxy[:user], proxy[:password],
+                        proxy[:uri].scheme == 'https')
         else
           Net::HTTP.new(env[:url].hostname, port, nil)
         end