Log Message:
py-test: updated to 3.8.1

pytest 3.8.1:

Bug Fixes
* .pytest_cache directory is now automatically ignored by Git. Users who would \ 
like to contribute a solution for other SCMs please consult/comment on this \ 
issue.
* Fix the following error during collection of tests inside packages:
  TypeError: object of type 'Package' has no len()
* Fix bug where indirect parametrization would consider the scope of all \ 
fixtures used by the test function to determine the parametrization scope, and \ 
not only the scope of the fixtures being parametrized.
* Fix crash of the assertion rewriter if a test changed the current working \ 
directory without restoring it afterwards.
* Fix issue that prevented some caplog properties (for example record_tuples) \ 
from being available when entering the debugger with --pdb.
* Fix UnicodeDecodeError in python2.x when a class returns a non-ascii binary \ 
__repr__ in an assertion which also contains non-ascii text.

Improved Documentation
* New Deprecations and Removals page shows all currently deprecated features, \ 
the rationale to do so, and alternatives to update your code. It also list \ 
features removed from pytest in past major releases to help those with ancient \ 
pytest versions to upgrade.

Trivial/Internal Changes
* Improve pre-commit detection for changelog filenames
* Remove legacy code around im_func as that was python2 only