Updated db/schema.rb: updated by pull request #65
fix update_histories link
Merge pull request #78 from lodge/fix_update_history_link

「編集履歴」がときたまコケる現象に対処
Added unicorn gem and modified config/unicorn.rb
Modified README
Merge remote-tracking branch 'origin/develop' into bootstrap

Conflicts:
	app/views/articles/show.html.erb
Fxied config/unicorn.rb

* If unicorn receieve USR2 signal, it'll re-execute master.
  But the old master still alive until it'll receive QUIT.
  So I've added explicit termination of the old master

* Improved logging. Replaced ``puts`` with logger.
  Also, changed to logfile to ``log/unicorn.ENV.log``.
Updated README
Update README.md
Modified unicorn.rb.erb
Update README.md
デザインをひと通り調整。
Merge remote-tracking branch 'origin/develop' into bootstrap