Merge pull request #842 from embark-framework/fix_cb_issue

take into account when event does not trigger a callback

lib/modules/ens/index.js

@@ -33,7 +33,7 @@ class ENS {
     this.events.setCommandHandler("storage:ens:associate", this.associateStorageToEns.bind(this));
   }
 
-  setProviderAndRegisterDomains(cb) {
+  setProviderAndRegisterDomains(cb = (() => {})) {
     const self = this;
     async.parallel([
       function getENSRegistry(paraCb) {