Update supported django versions. (#55)

* Updated supported django versions
* Include supported django versions to README.md

Author: jackton1

README.md

@@ -1,5 +1,8 @@
 # django-service-objects [![Latest Version][latest-version-image]][latest-version-link]
-[![Build Status][build-status-image]][build-status-link] [![Python Support][python-support-image]][python-support-link] [![License][license-image]][license-link]
+[![Build Status][build-status-image]][build-status-link] 
+[![Python Support][python-support-image]][python-support-link]
+[![PyPI - Django Version][django-version-image]][django-link]
+[![License][license-image]][license-link]
 
 Service objects for Django
 
@@ -160,5 +163,7 @@ If you have any questions about service objects, you can tweet me [@mixxorz](htt
 [build-status-link]: https://travis-ci.org/mixxorz/django-service-objects
 [python-support-image]: https://img.shields.io/pypi/pyversions/django-service-objects.svg
 [python-support-link]: https://pypi.org/project/django-service-objects/
+[django-version-image]: https://img.shields.io/pypi/djversions/django_service_objects.svg
+[django-link]: https://docs.djangoproject.com/en/3.0/releases/
 [license-image]: https://img.shields.io/pypi/l/django-service-objects.svg
 [license-link]: https://github.com/mixxorz/django-service-objects/blob/master/LICENSE

setup.py

@@ -42,7 +42,6 @@
         'Development Status :: 4 - Beta',
         'Environment :: Plugins',
         'Environment :: Web Environment',
-        'Framework :: Django',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: MIT License',
         'Operating System :: OS Independent',
@@ -54,6 +53,11 @@
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
+        'Framework :: Django :: 1.11',
+        'Framework :: Django :: 2.0',
+        'Framework :: Django :: 2.1',
+        'Framework :: Django :: 2.2',
+        'Framework :: Django :: 3.0',
         'Topic :: Internet :: WWW/HTTP',
         'Topic :: Internet :: WWW/HTTP :: Dynamic Content',
     ],