Log Message:
py-testtools: updated to 2.6.0

Release 2.6.0
* Finish adding support for Python 3.11
* Add a few missing entries to NEWS
* Wrap content-type params in a dictionary
* Replace deprecated \`cgi\` module usage with \`email\`
* Drop extras of extras; fixtures no longer uses it
* Fix distutilscmd in Debian + Py 3.11
* Add initial config for mypy
* Prevent AttributeError in TestCase.\_\_eq\_\_
* simplifying code
* less code
* Making sure that TestCase can be hashed
* Fix various test failures with Python 3.11
* Use CompoundFixture from fixtures>=2.0 rather than rolling our own
* Provide a \`\`testtools[twisted]\`\` extra
* Add final noop job to indicate success and set as required
* Fix DeprecationWarning: Only valid in 1.8.1 and earlier. Use skipTest instead
* Show warnings
* Replace deprecated assertRaisesRegexp with assertRaisesRegex
* Fix inclusion of NEWS in Sphinx documentation
* Upgrade Python syntax with pyupgrade --py36-plus
* Drop support for EOL Python 3.5
* Upgrade asserts with teyit for Python 3.11 compatibility
* doc: Remove references to unittest2
* Add instructions on building docs.
* Fix docstring formatting warnings
* Add missing quotes around identifier
* Drop note about assertIn, assertIs, assertIsInstance and their negatives that \ 
no longer applies with modern versions of Python.
* Fix typo.
* Deprecate distutils integration
* Add support for Python 3.10