Add explicit check for --watchAll=false (#7433)
Add explicit check for --watchAll=false (#7433)

Resolves #7180.
GreenGremlin/create-react-app,GreenGremlin/create-react-app,jdcrensh/create-react-app,Timer/create-react-app,facebookincubator/create-react-app,jdcrensh/create-react-app,Timer/create-react-app,Timer/create-react-app,jdcrensh/create-react-app,d3ce1t/create-react-app,facebookincubator/create-react-app,jdcrensh/create-react-app,GreenGremlin/create-react-app,facebookincubator/create-react-app,d3ce1t/create-react-app,d3ce1t/create-react-app,GreenGremlin/create-react-app,Timer/create-react-app,d3ce1t/create-react-app