Log Message:
py310-testtools: update to 2.5.0.

2.5.0
~~~~~

Improvements
------------

* Add support for Python 3.9.
  (Hugo van Kemenade)

* Python 3.5 has reached end-of-life and this is the last release to support it.

* The skip, skipIf, and skipUnless decorators can now be used as class
  decorators as well as test method decorators, just as they can in
  unittest.

* The ``SameMembers`` matcher class is now exposed as part of the public
  matchers API.

Changes
-------

* The dependency on the ``unittest2`` module has been removed. This has some
  knock on effects, including the removal of the ``assertItemsEqual`` helper
  which was removed from ``unittest`` in Python 3.x.

* The ``safe_hasattr`` utility has been removed from ``testtools.helpers``.
  This was a compat wrapper introduced in 0.9.25 when the utility itself was
  moved to the ``extras`` package. It is no longer useless on Python 3-only
  projects.

* The ``try_imports`` utility has been removed from ``testtools.helpers``.
  This was a compat wrapper introduced in 0.9.25 when the utility itself was
  moved to the ``extras`` package. It is no longer used within testtools and
  has therefore been dropped.