[JRO] Add dev dependencies to README
[JRO] Add dev dependencies to README

jvoss/thredded,prohippocoder/thredded,thredded/thredded,thredded/thredded,thredded/thredded,jvoss/thredded,jvoss/thredded,jvoss/thredded,jayroh/thredded,prohippocoder/thredded,jayroh/thredded,prohippocoder/thredded,thredded/thredded,jayroh/thredded,prohippocoder/thredded,jayroh/thredded