Testing attributes

[johnomotani]

When a new version of boutdata is released (0.1.3), we should be able to use assert_identical instead of assert_equals in

xBOUT/xbout/tests/test_boutdataset.py

Line 842 in 4b4fc97

def test_save_all(self, tmpdir_factory, bout_xyt_example_files):

and

xBOUT/xbout/tests/test_boutdataset.py

Line 862 in 4b4fc97

@pytest.mark.parametrize("geometry", [None, "toroidal"])

because that release will add the BoutOptions.__eq__() method, which should allow all the attributes of the Dataset to pass the tests.

Might be a few other places we could update to assert_identical instead of assert_equal as well?