Removed the need for pushy.

We've had issues with running using pushy on our servers -- for some reason it would timeout the request (Ubuntu 12.04.03 on both sides). I've replaced it with a simpler solution:

1. Executing `os.path.join` on the remote machine via simple execution and output capturing. We could execute `os.path.join` on the local machine, but then we need to make sure that the remote and local have same OS (or at least same kind).

2. Executing `ls` on the remote instead of glob.