Move tokenserializer import after otpseed definition

otpauth/models.py

@@ -1,9 +1,8 @@
 from django.db import models
 from django.contrib.auth.models import AbstractUser
-
 from rest_framework import exceptions
 from rest_framework import authentication
-from otpauth.serializer import TokenSerializer
+
 
 class OTPSeed(AbstractUser):
     id       = models.AutoField(primary_key=True)
@@ -17,6 +16,8 @@ class OTPSeed(AbstractUser):
     def __str__(self):
         return "'{}'@{}".format(self.name, self.realm)
 
+from otpauth.serializer import TokenSerializer
+
 class OTPAuthentication(authentication.BaseAuthentication):
     def authenticate(self, request):
         serializer = TokenSerializer(data=request.data)