Ignore __esModule field

Author: corlaez

packages/node_modules/overmind/src/utils.ts

@@ -30,6 +30,10 @@ export const makeStringifySafeMutations = (mutations: IMutation[]) => {
 export function deepCopy(obj) {
   if (isPlainObject(obj)) {
     return Object.keys(obj).reduce((aggr: any, key) => {
+      if (key === '__esModule') {
+        return aggr
+      }
+
       const originalDescriptor = Object.getOwnPropertyDescriptor(obj, key)
       const isAGetter = originalDescriptor && 'get' in originalDescriptor
       const value = obj[key]