Fix #230: Couldn't invite users(failed to create)

lib/models/user.js

@@ -587,7 +587,7 @@ module.exports = function(crowi) {
       emailList,
       function(email, next) {
         var newUser = new User()
-          ,password;
+          ,tmpUsername, password;
 
         email = email.trim();
 
@@ -605,8 +605,10 @@ module.exports = function(crowi) {
             return next();
           }
 
+          tmpUsername = 'temp_' + Math.random().toString(36).slice(-16);
           password = Math.random().toString(36).slice(-16);
 
+          newUser.username = tmpUsername;
           newUser.email = email;
           newUser.setPassword(password);
           newUser.createdAt = Date.now();
@@ -619,7 +621,7 @@ module.exports = function(crowi) {
                 password: null,
                 user: null,
               });
-              debug('save failed!! ', email);
+              debug('save failed!! ', err);
             } else {
               createdUserList.push({
                 email: email,