Remove Travis cruft and update changelog.

.travis.yml

@@ -1,27 +0,0 @@
-language: python
-dist: xenial
-cache: pip
-python:
-- '3.6'
-- '3.7'
-- '3.8'
-- '3.9'
-- pypy3
-services:
-- redis-server
-install: pip install tox-travis codecov
-script: tox
-after_success:
-- codecov
-deploy:
-  provider: pypi
-  user: jazzband
-  server: https://jazzband.co/projects/django-defender/upload
-  distributions: sdist bdist_wheel
-  skip_existing: true
-  password:
-    secure: d/PVFgBDMpG6UvBOxXBLH4vc7+tiPsjhq4YLgXfX0iXbdNHUnnCyDLg/XUQ7x0e7kRj+lhmBzytZxu3IpOY+5MuWk4JTqwoBHGuUlmTC9XEVvioqd/nFW7qVe36YKZHKuMDlmwBNQarJZdSBUFAoCfklZKI09sXA1qc8E3BLAb8=
-  on:
-    tags: true
-    repo: jazzband/django-defender
-    python: 3.7

CHANGES.rst

@@ -2,6 +2,11 @@
 Changes
 =======
 
+Unreleased
+----------
+
+- Move CI to GitHub Actions.
+
 0.8.0
 -----