Adds joined_date to the user admin

tournaments/admin.py

@@ -15,7 +15,7 @@ class CustomUserAdmin(UserAdmin):
     form = CustomUserChangeForm
     add_form = CustomUserCreationForm
     model = CustomUser
-    list_display = ['email', 'username', 'is_active', 'is_staff', 'first_name', 'last_name', ]
+    list_display = ['email', 'username', 'is_active', 'is_staff', 'first_name', 'last_name', 'date_joined']
     fieldsets = [
         (None, {'fields': ['id', 'username', 'email', 'password', 'first_name', 'last_name', 'is_active',
             'clubs', 'country', 'phone', 'licence_id', 'umpire_code',