added deflater middleware to gzip json responses

config/application.rb

@@ -21,6 +21,8 @@ module ControlPanel
     # Initialize configuration defaults for originally generated Rails version.
     # Initialize configuration defaults for originally generated Rails version.
     config.load_defaults 5.1
     config.load_defaults 5.1
 
 
+    config.middleware.use Rack::Deflater
+
     # Settings in config/environments/* take precedence over those specified here.
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration should go into files in config/initializers
     # Application configuration should go into files in config/initializers
     # -- all .rb files in that directory are automatically loaded.
     # -- all .rb files in that directory are automatically loaded.