add model sentences
add model after unit test
add controller before unit test
controller
fix controleer
merge develop
modify db
Merge branch 'add_sentences' of github.com:shimokitabenbot/shimokitabenbot into add_sentences

Conflicts:
	app/controllers/tweet_controller.rb
add spec
add regist sentence
add sentence search
add search unit test
Merge pull request #41 from shimokitabenbot/add_sentences

Add sentences