Support Django 2 new import location.

disposable_email_checker/validators.py

@@ -7,9 +7,16 @@
 from django.core import validators
 from django.core.exceptions import ValidationError
 from django.utils.translation import ugettext_lazy as _
-from django.core.urlresolvers import get_callable
+
 from bdea.client import BDEAClient
 
+# Django moved the location of `get_callable` in Django 2.0. We have kept the original import for
+# backwards compatibility.
+try:
+    from django.core.urlresolvers import get_callable
+except ImportError:
+    from django.urls import get_callable
+
 
 class DisposableEmailChecker():
     """