Ignore empty folders when calculating the dirty state

[royriojas]

Steps to reproduce:

On a repo with a clean state

1. Create an empty file, add it and commit it.
2. Create Emtpy Folder
3. Do a git status (verify status report all goo)
4. Attempt to push your commit

Current Behavior

The prepush complains about a dirty state, if the user agree to stash, it will fail because there is nothing to stash.

Expected behavior:

Make the push if the prepush validation passes