replace reference to watch-test npm script by tdd in README. fixes #2216
replace reference to watch-test npm script by tdd in README. fixes #2216

dozoisch/react-bootstrap,apkiernan/react-bootstrap,glenjamin/react-bootstrap,glenjamin/react-bootstrap,react-bootstrap/react-bootstrap,HPate-Riptide/react-bootstrap,react-bootstrap/react-bootstrap,mmarcant/react-bootstrap,react-bootstrap/react-bootstrap