* skip tests where one parameterize dimension was empty
* Fix Xfail does not work with condition keyword argument.
* Fix win32 path issue when puttinging custom config file with absolute
path in ``pytest.main("-c your_absolute_path")``.
* Fix maximum recursion depth detection when raised error class is not
aware of unicode/encoded bytes.
* Fix ``pytest.mark.skip`` mark when used in strict mode.
* Minor improvements and fixes to the documentation.
* Fix ``--fixtures`` to show all fixture definitions as opposed to just
one per fixture name.
- Do not ignore imports which are present and have been added after the
minimum version
- Ignore imports which became mandatory with the minimum version
- Add two older future imports
- Issue an error when a future import does not exist
- Define which is the oldest Python version to be supported so that
already mandatory features can be ignored and not yet supported
features default to forbidden (ignoring the lower error code).
- Use return code of 1 if errors occurred
While this makes things a little more complicated and means we'll need to use
`-r` to recreate tox environments, it has several advantages:
- Full support from requires.io (including PRs)
- Workaround for https://bitbucket.org/hpk42/tox/issues/332/ so we can update
virtualenv/pip
