combine-login-and-registration

http://stackoverflow.com/questions/13840802/how-to-properly-combine-login-and-registration-form-in-one-view

* $ rails g controller registrations
* $ rails g controller sessions
* update controllers
* update views
Revert "combine-login-and-registration"

This reverts commit fe886cd37d38bd944add214f65bc2fa1f0804a6d.
adding form helpers

-simple_form gem
* gem 'simple_form'
* $ rails generate simple_form:install --foundation

-country_select gem
* gem 'country_select'