Closes webpack dev server and exits process on "end" stdin (#7203)
Closes webpack dev server and exits process on "end" stdin (#7203)

Co-authored-by: Ian Schmitz <c11a1492b0e99ea2c9f3448509a3f2885774c45a@gmail.com>
facebookincubator/create-react-app,jdcrensh/create-react-app,Timer/create-react-app,Timer/create-react-app,jdcrensh/create-react-app,d3ce1t/create-react-app,d3ce1t/create-react-app,jdcrensh/create-react-app,facebookincubator/create-react-app,jdcrensh/create-react-app,d3ce1t/create-react-app,Timer/create-react-app,Timer/create-react-app,facebookincubator/create-react-app,d3ce1t/create-react-app