Fix git/hg detection in sub directories

[varac]

Before, detecting whether tests are run in a git/hg versioned
project was only successful when running them from the root
directory.
This resulted in a "unversioned" commit_info.id.

This change fixes git/hg repo detection and properly sets the
commit_info.id even when running in a sub directory.

[ionelmc]

Good catch but perhaps there's a better way that also work on windows? Wouldn't just looking for .hg/.git dirs up to 10 (or so) parent dirs be enough?

[varac]

@ionelmc Why would my change not work on windows ?

[ionelmc]

No such thing as /dev/null on Windows. A better way is to use the subprocess module. An even better way is to check that the directories exist (check few parents).

[varac]

oh sure. I'll check subprocess, because I thinks it's easier to use git/hg itself to determine if it's a git/hg repo. There will be someone who will come around with 11 layers of sudirectories :D

[varac]

Ok this should work on Windows as well now.

[ionelmc]

Alright, thanks.

[varac]

Thx !