Create Work model
rake db:migrate
Create WorksController
Create works_controller_spec
Enable feature of create works
Update works_controller_spec
Enable feature of edit works
Update works_controller_spec
Enable feature of delete works
Enable feature of done check works
Merge pull request #7 from ahkr/feature/works

ワークの追加、編集、削除、doneチェック機能を追加