add support for named captures

Signed-off-by: Konstantin Haase <konstantin.mailinglists@googlemail.com>

lib/sinatra/base.rb

@@ -1090,6 +1090,8 @@ module Sinatra
           [/^#{pattern}$/, keys]
         elsif path.respond_to?(:keys) && path.respond_to?(:match)
           [path, path.keys]
+        elsif path.respond_to?(:names) && path.respond_to?(:match)
+          [path, path.names]
         elsif path.respond_to? :match
           [path, keys]
         else