chore(package): update react-dom to version 15.4.2 (#1129)
chore(package): update react-dom to version 15.4.2 (#1129)

https://greenkeeper.io/
Semantic-Org/Semantic-UI-React,koenvg/Semantic-UI-React,mohammed88/Semantic-UI-React,vageeshb/Semantic-UI-React,clemensw/stardust,aabustamante/Semantic-UI-React,aabustamante/Semantic-UI-React,aabustamante/Semantic-UI-React,vageeshb/Semantic-UI-React,koenvg/Semantic-UI-React,clemensw/stardust,Semantic-Org/Semantic-UI-React,Rohanhacker/Semantic-UI-React,mohammed88/Semantic-UI-React,Rohanhacker/Semantic-UI-React