Remove old Travis cruft.

.travis.yml

@@ -1,36 +0,0 @@
-version: ~> 1.0
-dist: bionic
-os: linux
-language: python
-cache: pip
-python:
-- 3.6
-- 3.7
-- 3.8
-- 3.9
-arch:
-  - amd64
-  - ppc64le
-jobs:
-  include:
-    - python: 3.8
-      env: TOXENV=flake8
-install: pip install tox-travis codecov
-# positional args ({posargs}) to pass into tox.ini
-script: tox -- --cov --cov-append
-addons:
-  postgresql: '10'
-services:
-  - postgresql
-after_success: codecov
-deploy:
-  provider: pypi
-  username: jazzband
-  server: https://jazzband.co/projects/django-model-utils/upload
-  distributions: sdist bdist_wheel
-  password:
-    secure: JxUmEdYS8qT+7xhVyzmVD4Gkwqdz5XKxoUhKP795CWIXoJjtlGszyo6w0XfnFs0epXtd1NuCRXdhea+EqWKFDlQ3Yg7m6Y/yTQV6nMHxCPSvicROho7pAiJmfc/x+rSsPt5ag8av6+S07tOqvMnWBBefYbpHRoel78RXkm9l7Mc=
-  on:
-    tags: true
-    repo: jazzband/django-model-utils
-    python: 3.6

README.rst

@@ -5,8 +5,8 @@ django-model-utils
 .. image:: https://jazzband.co/static/img/badge.svg
    :target: https://jazzband.co/
    :alt: Jazzband
-.. image:: https://travis-ci.org/jazzband/django-model-utils.svg?branch=master
-   :target: https://travis-ci.org/jazzband/django-model-utils
+.. image:: https://github.com/jazzband/django-model-utils/workflows/Test/badge.svg
+   :target: https://github.com/jazzband/django-model-utils/actions
 .. image:: https://codecov.io/gh/jazzband/django-model-utils/branch/master/graph/badge.svg
   :target: https://codecov.io/gh/jazzband/django-model-utils
 .. image:: https://img.shields.io/pypi/v/django-model-utils.svg