Prevent permission denied when cloning

Without read permission to the current working directory, git-clone will
fail:
root@host:~$ sudo -u git -H git clone \
  git://github.com/ansible/ansible.git /home/git/ansible
fatal: Could not change back to '/root': Permission denied

This commit ensures that the working directory is changed to the
parent-folder of the destination before doing the clone.
Merge pull request #1864 from eval/git-module-prevent-permission-denied

Prevent permission denied when cloning