Release 2.1.2

[nicoddemus]

Also attempt to fix #177

[nicoddemus]

Couldn't really get rid of this call to tox using sudo:

Obtaining file:///home/travis/build/nicoddemus/pytest-qt
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "/home/travis/build/nicoddemus/pytest-qt/.tox/lint/lib/python3.4/site-packages/setuptools/dist.py", line 418, in fetch_build_egg
        cmd = self._egg_fetcher
    AttributeError: 'Distribution' object has no attribute '_egg_fetcher'
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File "/home/travis/build/nicoddemus/pytest-qt/.tox/lint/lib/python3.4/site-packages/setuptools/command/easy_install.py", line 462, in check_site_dir
        open(testfile, 'w').close()
    PermissionError: [Errno 13] Permission denied: './.eggs/test-easy-install-5916.write-test'
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/home/travis/build/nicoddemus/pytest-qt/setup.py", line 61, in <module>
        cmdclass={'test': PyTest},
      File "/opt/python/3.4.6/lib/python3.4/distutils/core.py", line 108, in setup
        _setup_distribution = dist = klass(attrs)
      File "/home/travis/build/nicoddemus/pytest-qt/.tox/lint/lib/python3.4/site-packages/setuptools/dist.py", line 320, in __init__
        self.fetch_build_eggs(attrs['setup_requires'])
      File "/home/travis/build/nicoddemus/pytest-qt/.tox/lint/lib/python3.4/site-packages/setuptools/dist.py", line 377, in fetch_build_eggs
        replace_conflicting=True,
      File "/home/travis/build/nicoddemus/pytest-qt/.tox/lint/lib/python3.4/site-packages/pkg_resources/__init__.py", line 852, in resolve
        dist = best[req.key] = env.best_match(req, ws, installer)
      File "/home/travis/build/nicoddemus/pytest-qt/.tox/lint/lib/python3.4/site-packages/pkg_resources/__init__.py", line 1124, in best_match
        return self.obtain(req, installer)
      File "/home/travis/build/nicoddemus/pytest-qt/.tox/lint/lib/python3.4/site-packages/pkg_resources/__init__.py", line 1136, in obtain
        return installer(requirement)
      File "/home/travis/build/nicoddemus/pytest-qt/.tox/lint/lib/python3.4/site-packages/setuptools/dist.py", line 443, in fetch_build_egg
        cmd.ensure_finalized()
      File "/opt/python/3.4.6/lib/python3.4/distutils/cmd.py", line 107, in ensure_finalized
        self.finalize_options()
      File "/home/travis/build/nicoddemus/pytest-qt/.tox/lint/lib/python3.4/site-packages/setuptools/command/easy_install.py", line 320, in finalize_options
        self.check_site_dir()
      File "/home/travis/build/nicoddemus/pytest-qt/.tox/lint/lib/python3.4/site-packages/setuptools/command/easy_install.py", line 465, in check_site_dir
        self.cant_write_to_target()
      File "/home/travis/build/nicoddemus/pytest-qt/.tox/lint/lib/python3.4/site-packages/setuptools/command/easy_install.py", line 528, in cant_write_to_target
        raise DistutilsError(msg)
    distutils.errors.DistutilsError: can't create or remove files in install directory
    
    The following error occurred while trying to add or remove files in the
    installation directory:
    
        [Errno 13] Permission denied: './.eggs/test-easy-install-5916.write-test'
    
    The installation directory you specified (via --install-dir, --prefix, or
    the distutils default setting) was:
    
        ./.eggs
    
    Perhaps your account does not have write access to this directory?  If the
    installation directory is a system-owned directory, you may need to sign in
    as the administrator or "root" account.  If you do not have administrative
    access to this machine, you may wish to choose a different installation
    directory, preferably one that is listed in your PYTHONPATH environment
    variable.
    
    For information on other options, you may wish to consult the
    documentation at:
    
      https://setuptools.readthedocs.io/en/latest/easy_install.html
    
    Please make the appropriate changes for your system and try again.
    
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /home/travis/build/nicoddemus/pytest-qt/

[coveralls]

Coverage remained the same at 100.0% when pulling 35ce2f6 on nicoddemus:release-2.1.2 into ed7a0ed on pytest-dev:master.