Added a changelog to the project

Helps to make it easier for users and contributors to see precisely what
notable changes have been made between each release of the project.

Follows practices described by "keep a changelog". For additional
details, see: http://keepachangelog.com/

Include all past releases and include their dates. The dates were
determined by the PyPI data and git tags.

Tried to fill in notable changes where it was easy to understand
changes.

CHANGELOG

@@ -0,0 +1,77 @@
+UNRELEASED
+==========
+
+- Fixed dependencies to keep Django 1.11 support.
+- ``Event.calendar`` is now ``null=True``. Existing ``Event`` objects without a
+  calendar will be assigned to a calendar named "default".
+
+
+0.8.7 - 2018-01-09
+==================
+
+- Added support for Django 2.0.
+- Removed support for Django < 1.11.
+- Removed support for end of life Python 3.3.
+- Removed ``SCHEDULER_BASE_CLASSES`` setting.
+- ``Calendar.slug`` is now ``unique=True``.
+- To improve query performance, generic foreign keys are now ``db_index=True``.
+
+
+0.8.6 - 2017-07-30
+==================
+
+- Fixed admin to use ``SCHEDULER_ADMIN_FIELDS`` for ``Calendar``.
+- Fixed compatibility with dateutil 2.6.1.
+- Added missing migration for the ``Calendar`` ``verbose_name`` option.
+
+
+0.8.5 - 2017-06-25
+==================
+
+- Model fields of type ``CharField`` or ``TextField`` are now ``null=False``.
+  Use an empty string, ``''``, to represent no data.
+- ``feeds/atom.py`` has been removed. Use Django's syndication feed framework
+  instead.
+- Added setting ``SCHEDULER_ADMIN_FIELDS`` to add additional fields to be added
+  to admin forms.
+- Changed ``Callendar`` ``verbose_name`` to "calendars".
+
+
+0.8.4 - 2017-04-09
+==================
+
+- Now distributed as a universal wheel.
+- Added view ``schedule`` that lists all calendars.
+- Changed setting ``SCHEDULER_BASE_CLASSES`` to support extending specific
+  models.
+
+
+0.8.3 - 2017-02-01
+==================
+
+0.8.2 - 2016-12-03
+==================
+
+0.8.1 - 2016-11-08
+==================
+
+0.8.0 - 2016-05-04
+==================
+
+0.7.5 - 2015-05-16
+==================
+
+0.7.4 - 2015-01-11
+==================
+
+0.7.3 - 2014-11-03
+==================
+
+0.7.2 - 2014-04-26
+==================
+
+0.7.1 - 2013-11-12
+==================
+
+0.6.1 - 2013-07-26
+==================

MANIFEST.in

@@ -1,3 +1,4 @@
+include CHANGELOG
 include LICENSE.txt
 include README.md
 recursive-include docs *

docs/changelog.txt

@@ -0,0 +1,5 @@
+=========
+Changelog
+=========
+
+.. include:: ../CHANGELOG

docs/index.txt

@@ -16,6 +16,7 @@ DjangoSchedule is an open-source calendaring application.
     views
     models
     settings
+    changelog
 
 
 Indices and tables