Sandbox root folders missing 2 random files!

Strainer is failing on my Jenkins box, and on examination the Sandbox doesn't believe my chef repo is a chef repo as it's missing some of the expected directories. They're actually there and it seems the root folders code is throwing away 2 filenames - I suspect this was meant to be '.' and '..' but these aren't always at the front of a glob.

Replace this code with an explicit rejection of '.' and '..' and strainer works again on all boxes.