Handle unmatched routing with not_found method

We need this to prevent routing error when user access URL like /123
when there is no resource located under such name

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/controllers/application_controller.rb

@@ -45,6 +45,10 @@ class ApplicationController < ActionController::Base
     redirect_to request.referer.present? ? :back : default, options
   end
+  def not_found
+    render_404
+  end
+
   protected
   # This filter handles both private tokens and personal access tokens

config/routes.rb

@@ -88,4 +88,6 @@ Rails.application.routes.draw do
   get ':username.keys' => 'profiles/keys#get_keys', constraints: { username: /.*/ }
   root to: "root#index"
+
+  get '*unmatched_route', to: 'application#not_found'
 end