Log Message:
py-test: updated to 3.6.3

3.6.3:
Bug Fixes
* Fix ImportWarning triggered by explicit relative imports in \ 
assertion-rewritten package modules.
* Fix error in pytest.approx when dealing with 0-dimension numpy arrays.
* No longer raise ValueError when using the get_marker API.
* Fix problem where log messages with non-ascii characters would not appear in \ 
the output log file.
* No longer raise AttributeError when legacy marks can’t be stored in functions.

Improved Documentation
* The description above the example for @pytest.mark.skipif now better matches \ 
the code.

Trivial/Internal Changes
* Internal refactoring: removed unused CallSpec2tox ._globalid_args attribute \ 
and metafunc parameter from CallSpec2.copy().
* Silence usage of reduce warning in Python 2
* Fix usage of attr.ib deprecated convert parameter