[all] remove Travis CI

As far as I can tell, Travis CI is *not* free anymore, even for OSS
projects. I assumed the 10k credits were monthly or yearly, but
seemingly, they are a one-time thing.

So, remove Travis CI and start searching for a better replacement.

see #906

.travis.yml

@@ -1,30 +0,0 @@
-os: linux
-language: python
-env:
-  global:
-    - CC_TEST_REPORTER_ID=40cb00907f7a10e04868e856570bb997ab9c42fd3b63d980f2b2269433195fdf 
-python:
-  - "3.6"
-  - "3.7"
-  - "3.8"
-  - "3.9"
-before_script:
-  - curl -L https://codeclimate.com/downloads/test-reporter/test-reporter-latest-linux-amd64 > ./cc-test-reporter
-  - chmod +x ./cc-test-reporter
-  - ./cc-test-reporter before-build
-addons:
-  apt:
-    packages:
-      libdbus-1-dev
-      libgit2-dev
-      libvirt-dev
-      taskwarrior
-install:
-  - pip install -U coverage pytest pytest-mock freezegun
-  - pip install 'pygit2<1' 'libvirt-python<6.3' 'feedparser<6' || true
-  - pip install $(cat requirements/modules/*.txt | cut -d ' ' -f 1 | sort -u)
-script:
-  - coverage run --source=. -m pytest tests -v
-after_script:
-  - coverage xml
-  - ./cc-test-reporter after-build --exit-code $TRAVIS_TEST_RESULT

CONTRIBUTING.md

@@ -12,6 +12,5 @@ But even if you can't provide those, any indicator that something is not working
 
 ### Adding a new module or theme
 If you want to add a new module, please have a look at [how to write a new module](docs/development/module.rst) and [how to write a new theme](docs/development/theme.rst). Then simply create a Pull Request and I will review the changes as soon as possible.
-If you want to do me a *big* favour, check the Travis status for any failing unit tests. Oh - and if you happen to add unit tests, that's also something I am very grateful for!
 
 Thanks for reading until here! :)

README.md

@@ -1,6 +1,5 @@
 # bumblebee-status
 
-[![Build Status](https://app.travis-ci.com/tobi-wan-kenobi/bumblebee-status.svg?branch=main)](https://app.travis-ci.com/tobi-wan-kenobi/bumblebee-status)
 [![Documentation Status](https://readthedocs.org/projects/bumblebee-status/badge/?version=main)](https://bumblebee-status.readthedocs.io/en/main/?badge=main)
 ![AUR version (release)](https://img.shields.io/aur/version/bumblebee-status)
 ![AUR version (git)](https://img.shields.io/aur/version/bumblebee-status-git)

versioneer.py

@@ -14,8 +14,6 @@ The Versioneer
 (https://pypip.in/version/versioneer/badge.svg?style=flat)
 ](https://pypi.python.org/pypi/versioneer/)
 * [![Build Status]
-(https://travis-ci.org/warner/python-versioneer.png?branch=master)
-](https://travis-ci.org/warner/python-versioneer)
 
 This is a tool for managing a recorded version number in distutils-based
 python projects. The goal is to remove the tedious and error-prone "update