Updated /home/git paths to /home/dokku to reflect changes in dokku.

Recent dokku commit (https://github.com/progrium/dokku/commit/b5c8dd7436d9a938c188b10be17e9f2fd9d35933) changed the dokku root path to: `/home/dokku/` instead of `/home/git/`. Thus, running the chef recipes failed.

This commit updates the paths correctly. All ChefSpec tests pass.