update react-toastr to v2.8.0

Author: AllenFang

package.json

@@ -64,7 +64,7 @@
   },
   "dependencies": {
     "classnames": "^2.1.2",
-    "react-toastr": "^2.3.1"
+    "react-toastr": "^2.8.0"
   },
   "peerDependencies": {
     "react": "^0.14.3 || ^15.0.0"