adding direnv dependency
removing unused functions
New `vm` and `serve` commands.

 - vm: alias for vagrant, first changing the working directory to a path
   set in an environment variable that contains the development
   Vagrantfile and ansible playbooks on the machine
 - serve: Updates the symlink at ~/.app to the passed target and reloads
   the vagrant virtual machine.
Adding sup command, jumps to and serves the directory via vagrant