plugin: pass block further, also request: do not convert to string, nonw that we'll have signatures

lib/httpx/chainable.rb

@@ -34,11 +34,11 @@ module HTTPX
       branch(default_options).wrap(&blk)
     end
 
-    def plugin(*args, **opts)
+    def plugin(*args, **opts, &blk)
       klass = is_a?(Session) ? self.class : Session
       klass = Class.new(klass)
       klass.instance_variable_set(:@default_options, klass.default_options.merge(default_options))
-      klass.plugin(*args, **opts).new
+      klass.plugin(*args, **opts, &blk).new
     end
 
     # deprecated

lib/httpx/request.rb

@@ -45,7 +45,7 @@ module HTTPX
 
     def initialize(verb, uri, options = {})
       @verb    = verb.to_s.downcase.to_sym
-      @uri     = URI(uri.to_s)
+      @uri     = URI(uri)
       @options = Options.new(options)
 
       raise(Error, "unknown method: #{verb}") unless METHODS.include?(@verb)