fix(package): update react-addons-css-transition-group to version 15.5.2 (#2283)
fix(package): update react-addons-css-transition-group to version 15.5.2 (#2283)

Closes #2252

https://greenkeeper.io/
kumar303/addons-frontend,kumar303/addons-frontend,aviarypl/mozilla-l10n-addons-frontend,kumar303/addons-frontend,mozilla/addons-frontend,kumar303/addons-frontend,mozilla/addons-frontend,aviarypl/mozilla-l10n-addons-frontend,tsl143/addons-frontend,tsl143/addons-frontend,tsl143/addons-frontend,aviarypl/mozilla-l10n-addons-frontend,mozilla/addons-frontend,tsl143/addons-frontend,mozilla/addons-frontend,aviarypl/mozilla-l10n-addons-frontend