fix #3498 - correctly consider marks on unittest classes

[RonnyPfannschmidt]

Thanks for submitting a PR, your contribution is really appreciated!

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[coveralls]

Coverage increased (+0.05%) to 92.742% when pulling bc25d51 on RonnyPfannschmidt:fix-3498-unittest-marks into afde9f0 on pytest-dev:master.

[nicoddemus]

We never install unittest2, should we add it to our testing dependencies in tox.ini?

[RonnyPfannschmidt]

atm i dont think thats necessary

[owenleonard]

I pulled down the changes and verified they work correctly for my use cases. Thanks for such a quick response!

[nicoddemus]

Thanks @RonnyPfannschmidt!

We should have a 3.6.1 release soon