Encourage using Rails for API development

Summary
-------
* Update rails to 4.0.11
* remove haml
* remove simple form
* remove jquery rails
* remove konacha
* remove capybara
* remove poltergeist
* remove launchy
* remove headless
* remove fdoc
* remove anything related to assets
* remove better errors
* remove guard konacha
* add json spec
* add pry and binding of caller
* update readme