test_maya.py refactored: using parametrization where feasible
test_maya.py refactored: using parametrization where feasible

repeated code replaced by parameters provided by pytest.

source string and rexpected intentionally indented to match by column
to make checking year, month and date simpler.

Note, that the test_issue_104 was (and still is) failing.

timofurrer/maya,kennethreitz/maya