Update rails to version 4.2

Furthermore it was necessary to add the following gems:
- responders
- web-console

And additional it was necessary to update these gems manually:
- devise
- turbolinks
- delayed_job_active_record
- money-rails

And the corresponding dependencies.
http://edgeguides.rubyonrails.org/upgrading_ruby_on_rails.html#upgrading-from-rails-4-1-to-rails-4-2

INSTALL.md

@@ -29,7 +29,7 @@ We are using [Vagrant](https://www.vagrantup.com/) to create our development env
 7. Start your OSEM rails app:
 
     ```
-    vagrant exec rails s
+    vagrant exec rails server -b 0.0.0.0
     ```
 
 8. Check out your OSEM rails app: