Use newer react-toolbox beta and lower down required node version

Author: olegstepura

package.json

@@ -39,13 +39,13 @@
     "toolbox"
   ],
   "engines": {
-    "node": ">=7.4.0",
-    "npm": ">=4.0.5"
+    "node": ">=4.3.0",
+    "npm": ">=4.0.1"
   },
   "dependencies": {
     "react": "^15.4.2",
     "react-dom": "^15.4.2",
-    "react-toolbox": "^2.0.0-beta.4",
+    "react-toolbox": "^2.0.0-beta.5",
     "react-addons-css-transition-group": "^15.4.2"
   },
   "devDependencies": {