remove object-assign dep ( which was missing from package.json )

src/core/utils.js

@@ -1,5 +1,4 @@
 import Im from "immutable"
-import assign from "object-assign"
 import shallowEqual from "shallowequal"
 
 import camelCase from "lodash/camelCase"
@@ -85,7 +84,7 @@ export function objReduce(obj, fn) {
   return Object.keys(obj).reduce((newObj, key) => {
     let res = fn(obj[key], key)
     if(res && typeof res === "object")
-      assign(newObj, res)
+      Object.assign(newObj, res)
     return newObj
   }, {})
 }