make tests pass on Windows

[jurko-gospodnetic]

Currently there is one failing test on Windows:

def test_report_keys(num_processes, make_json):
    data = make_json()
    keys = set([
        'created', 'duration', 'environment', 'collectors', 'tests', 'summary',
        'root', 'exitcode'
    ])
    if num_processes > 0:
        # xdist only reports failing collectors
        keys.remove('collectors')
    assert set(data) == keys
    assert isinstance(data['created'], float)
    assert isinstance(data['duration'], float)
    assert data['root'].startswith('/')
    assert data['exitcode'] == 1

because it checks that data[root] starts with an '/' - and I expect we should instead check whether it's an absolute path using os.path.isabs()

[jurko-gospodnetic]

fixed in pull request #66

[numirias]

Thanks! The project doesn't currently aim to guarantee Windows compatibility, but I'll happily take patches like this one.