chore(package): update react-dom to version 15.2.1
chore(package): update react-dom to version 15.2.1

https://greenkeeper.io/
hairmot/REACTModuleTest,tylerhq/react-fifteen,Nekimola/react-training,roytang121/oled-visual,donghee214/pathway,SodhanaLibrary/react-examples,krystalcampioni/krystalcampioni-portfolio,liranhershko/intSights,roytang121/oled-visual,BlackCloudConcepts/geolocLang-react-simple,grohaus/schism-ecce-client,annaboodle/buddies,alicoding/react-webpack-babel,scaphold-io/slackr-graphql-subscriptions-starter-kit,brz0/chart-suite,scaphold-io/slackr-graphql-subscriptions-starter-kit,hairmot/REACTModuleTest,Nekimola/react-training,liranhershko/intSights,teemuteemu/sp_modular,krystalcampioni/krystalcampioni-portfolio,scottjbarr/companies-ui,annaboodle/buddies,alicoding/react-webpack-babel,teemuteemu/sp_modular,scottjbarr/companies-ui,brz0/chart-suite,kjhwee91/react-c3js,BlackCloudConcepts/geolocLang-react-simple,roytang121/oled-visual,grohaus/schism-ecce-client,donghee214/pathway,SodhanaLibrary/react-examples,tylerhq/react-fifteen