Drop Django 2.0 support

.travis.yml

@@ -11,13 +11,10 @@ matrix:
   fast_finish: true
 
   include:
-    - { python: "3.5", env: TOXENV=py35-django20 }
     - { python: "3.5", env: TOXENV=py35-django21 }
     - { python: "3.5", env: TOXENV=py35-django22 }
-    - { python: "3.6", env: TOXENV=py36-django20 }
     - { python: "3.6", env: TOXENV=py36-django21 }
     - { python: "3.6", env: TOXENV=py36-django22 }
-    - { python: "3.7", env: TOXENV=py37-django20 }
     - { python: "3.7", env: TOXENV=py37-django21 }
     - { python: "3.7", env: TOXENV=py37-django22 }
     - { python: "3.7", env: TOXENV=py37-djangomaster }

HISTORY.rst

@@ -6,6 +6,7 @@ History
 2.1.0 (unreleased)
 ------------------
 
+- Dropped Django 2.0 support
 - Dropped previously-deprecated ``Charge.fee_details`` property.
 - Dropped previously-deprecated ``Transfer.fee_details`` property.
 - Dropped previously-deprecated ``field_name`` parameter to ``sync_from_stripe_data``

djstripe/models/base.py

@@ -1,9 +1,7 @@
 import logging
 import uuid
-import warnings
 from datetime import timedelta
 
-import django
 from django.db import IntegrityError, models, transaction
 from django.utils import dateformat, timezone
 from django.utils.encoding import smart_text
@@ -318,13 +316,6 @@ def _attach_objects_post_save_hook(self, cls, data, pending_relations=None):
 					setattr(target, field.name, self)
 					target.save()
 
-					if django.VERSION < (2, 1):
-						# refresh_from_db doesn't clear related objects cache on django<2.1
-						# instead manually clear the instance cache so refresh_from_db will reload it
-						for field in self._meta.concrete_fields:
-							if field.is_relation and field.is_cached(self):
-								field.delete_cached_value(self)
-
 					# reload so that indirect relations back to this object - eg self.charge.invoice = self are set
 					# TODO - reverse the field reference here to avoid hitting the DB?
 					self.refresh_from_db()

setup.cfg

@@ -19,7 +19,6 @@ classifiers =
 	Programming Language :: Python :: 3.6
 	Programming Language :: Python :: 3.7
 	Framework :: Django
-	Framework :: Django :: 2.0
 	Framework :: Django :: 2.1
 	Framework :: Django :: 2.2
 
@@ -28,7 +27,7 @@ packages = find:
 include_package_data = True
 zip_safe = False
 install_requires =
-	Django >= 2.0
+	Django >= 2.1
 	jsonfield >= 2.0.2
 	stripe >= 2.3.0
 

tox.ini

@@ -1,9 +1,9 @@
 [tox]
 envlist =
-	py35-django{20,21,22}
-	py36-django{20,21,22}
-	py37-django{20,21,22,master}
 	py37-django21-checkmigrations
+	py35-django{21,22}
+	py36-django{21,22}
+	py37-django{21,22,master}
 	flake8
 
 [testenv]