Add '.status' method to RWS::Response::Item class.
Refactor spec files.
Add '.success?' method to instance of RWS::Response::Item.
Add '.errors' method to instance of RWS::Response::Item classes.
refactor RWS::Response::Item
update README.md
ver 0.1.1
Merge pull request #4 from kamiya54/dev

ver0.1.1