Add client sync test for dir becoming a file

[ckamm]

See owncloud/client#4302

[nickvergessen]

After https://github.com/owncloud/smashbox/pull/140 / https://github.com/cernbox/smashbox/issues/60 is merged, you can simply add

    if compare_client_version('2.1.0', '<='):
        logger.warning('Skipping test, because the client version is known to behave incorrectly')
        return

as first line in your workers definition to skip it for a given client version

[ckamm]

Note that the test currently fails with 2.1.1 beta 1 because the client reports version 2.1.1beta1 and the version check macro can't deal with the 'beta1' suffix. I'll make a ticket.

[nickvergessen]

Tested and works on master, stable9 and stable8.2 with client v2.1.1, branch 2.1

I think we can/should merge, @PVince81

[ckamm]

I'd be glad if this was merged, feel free to!

[PVince81]

:+1: