feat: pass host into WEBrick options to allow configuration (#128)

Co-authored-by: Matthew Hall <matthew.hall@partnerize.com>

Author: mhall58

lib/pact/consumer/server.rb

@@ -83,7 +83,7 @@ def get_identity
     end
 
     def webrick_opts
-      opts = { Port: port.nil? ? 0 : port, AccessLog: [], Logger: WEBrick::Log::new(nil, 0) }
+      opts = { Host: host.nil? ? 'localhost' : host, Port: port.nil? ? 0 : port, AccessLog: [], Logger: WEBrick::Log::new(nil, 0) }
       opts.merge!({
         :SSLCertificate => OpenSSL::X509::Certificate.new(File.open(options[:sslcert]).read) }) if options[:sslcert]
       opts.merge!({