Removing interface to Travis CI (#1261)

Patch by Bret McGuire; reviewed by Andy Tolbert and Bret McGuire
reference: https://github.com/apache/cassandra-python-driver/pull/1261

.travis.yml

diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 8593945..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,32 +0,0 @@
-dist: jammy
-sudo: false
-
-language: python
-python:
-  - "3.8"
-  - "3.9"
-  - "3.10"
-  - "3.11"
-
-env:
-  - CASS_DRIVER_NO_CYTHON=1
-
-addons:
-  apt:
-    packages:
-    - build-essential
-    - python3-dev
-    - pypy-dev
-    - libc-ares-dev
-    - libev4
-    - libev-dev
-
-install:
-  - pip install --upgrade setuptools importlib-metadata
-  - pip install tox-travis
-  - if [[ $TRAVIS_PYTHON_VERSION != pypy3.5 ]]; then pip install lz4; fi
-
-script:
-  - tox
-  - tox -e gevent_loop
-  - tox -e eventlet_loop