use hash argument in redirect

Author: allenwei

README.markdown

@@ -224,7 +224,7 @@ redirect "/new_url"
 use permanent redirect
 
 ``` ruby
-redirect "/new_url", true
+redirect "/new_url", :permanent => true
 ```
 
 ## Raising Errors

lib/grape/endpoint.rb

@@ -136,9 +136,11 @@ def error!(message, status=403)
     # Redirect to a new url.
     # 
     # @param url [String] The url to be redirect.
-    # @param permanent [Boolean] Whether use permanent redirect with status code 304.
-    def redirect(url, permanent=false)
-      if permanent
+    # @param options [Hash] The options used when redirect.
+    #                       :permanent, default true.
+    def redirect(url, options = {})
+      merged_options = {:permanent => false }.merge(options)
+      if merged_options[:permanent]
         status 304
       else
         if env['HTTP_VERSION'] == 'HTTP/1.1' && request.request_method.to_s.upcase != "GET"

spec/grape/endpoint_spec.rb

@@ -227,7 +227,7 @@ def app; subject end
 
     it "support permanent redirect" do 
       subject.get('/hey') do 
-        redirect "/ha", true
+        redirect "/ha", :permanent => true
       end
       get '/hey'
       last_response.status.should eq 304