chore: switch to python version 3.11

Author: b1r3k

.python-version

@@ -1 +1 @@
-3.6.8
+3.11

.travis.yml

@@ -1,6 +1,7 @@
 language: python
+dist: jammy
 python:
-  - "3.6"
+  - "3.11"
 # command to install dependencies
 install:
   - make dev

setup.py

@@ -32,6 +32,7 @@ def read(f):
 setup(
     name='content-validator',
     version=version,
+    python_requires='>=3.11',
     description=('Content validator looks at text content and preforms different validation tasks'),
     classifiers=[
         'License :: OSI Approved :: BSD License', 'Intended Audience :: Developers', 'Programming Language :: Python'