Fixes issues with doctests reported in #36 - class, package…and module didn't work because DoctestItem doesn't have cls or module attributes. Thanks @tobywf.
Deprecates none bucket type.
With tox, run tests of pytest-random-order with both pytest 3 and 4.
class
,package
…andmodule
didn't work becauseDoctestItem
doesn't havecls
ormodule
attributes. Thanks @tobywf.none
bucket type.