add style to users#show

* use 'Pure' css framework
* improve tempalte
improve form to edit user's profile

* partialize sidebar
* rename css
* apply style
add link to edit profile page

* add helper_method to check user is owner or not
* apply style
add link to back to profile page from edit page

* set name on path to /:nick
redirect to profile page after edit
set margin to flash_message
fix html structure

* partialize header of user page
* fix html structure
* specify width to sidebar (maybe dirty hack...)
start to implement user_profiles

* generate scaffold
rename unbiguous path name
add routing for user_profiles

* set 'resource' into namespace ':users'
 * access by '/users/profile'
modify and execute migration
specify relation between User and UserProfile
modify controller to fit to spec

* modify to singular resource
* modify before_action method
* remove unused templates
fix template issues

* specify form action when render partial
* fix named path to back to home
modify require group of 'pry-rails'
include Devise::TestHelpers
add controller spec for UserProfile
add style to create / update profile page

* use same partials
show resume on profile page
show resume on profile page

* add module 'Renderable' to render html from markdown