Move redirect macro to context def

src/kemal/context.cr

@@ -7,5 +7,10 @@ class HTTP::Server
     def params
       Kemal::ParamParser.new(@route, @request).parse
     end
+
+    def redirect(url)
+      @response.headers.add "Location", url
+      @response.status_code = 301
+    end
   end
 end

src/kemal/macros.cr

@@ -16,11 +16,6 @@ macro render(filename, layout)
   render {{layout}}
 end
 
-macro redirect(url)
-  env.response.headers.add "Location", {{url}}
-  env.response.status_code = 301
-end
-
 macro add_handler(handler)
   Kemal.config.add_handler {{handler}}
 end