Optimise imports

website/partners/api/serializers.py

-from django.utils import timezone
-from django.urls import reverse
-from rest_framework import serializers
-
 from events.api.serializers import CalenderJSSerializer
 from partners.models import PartnerEvent
 

website/partners/models.py

-from django.db import models
 from django.core.validators import RegexValidator, URLValidator
+from django.db import models
 from django.urls import reverse
-from django.utils.translation import ugettext, ugettext_lazy as _, \
-    string_concat
-
-from utils.translation import MultilingualField, ModelTranslateMeta
+from django.utils.translation import ugettext_lazy as _
 from tinymce.models import HTMLField
+from utils.translation import MultilingualField, ModelTranslateMeta
 
 
 class Partner(models.Model):