Remove Rails 3 attr_accessors

We don't have to add other code for Rails 4 Strong Parameters.
Replace /views to app/views in conjunction with other view path.
Merge pull request #127 from sho-h/remove-rails3-accessors

Remove Rails 3 attr_accessors
Merge pull request #128 from sho-h/fix-view-path

Replace /views to app/views in conjunction with other view path.