use react-transition-group package

swaps out react-addons-css-transition-group (no longer supported by the React team) for react-transition-group

see the React v15.5 blog post for more context: https://facebook.github.io/react/blog/2017/04/07/react-v15.5.0.html#discontinuing-support-for-react-addons

Author: Ali Ukani

package.json

@@ -14,7 +14,7 @@
     "prepublish": "npm run build"
   },
   "dependencies": {
-    "react-addons-css-transition-group": "^15.0.0"
+    "react-transition-group": "^1.1.1"
   },
   "peerDependencies": {
     "react": "^15.0.0",

src/ReactCSSTransitionReplace.jsx

@@ -7,7 +7,7 @@
 import React from 'react'
 import ReactDOM from 'react-dom'
 
-import ReactCSSTransitionGroupChild from 'react/lib/ReactCSSTransitionGroupChild'
+import ReactCSSTransitionGroupChild from 'react-transition-group/CSSTransitionGroupChild'
 
 const reactCSSTransitionGroupChild = React.createFactory(ReactCSSTransitionGroupChild)