Well, playing with otto is off to a GREAT start...

gistfile1.txt

$ otto dev
Would you like Otto to install Vagrant?
  An older version of vagrant was found installed (1.6.3). Otto requires
  version 1.8.1 or higher. Otto can install the latest version of vagrant
  for you (1.8.1). Would you like Otto to update vagrant for you?

  Please enter 'yes' to continue. Any other value will exit.

  Enter a value: yes

==> Downloading Vagrant v1.8.1...
    URL: https://releases.hashicorp.com/vagrant/1.8.1/vagrant_1.8.1.dmg

    87.9 MB/87.9 MB
[otto] Attaching Vagrant disk image...
[otto] Starting Vagrant installer...
Password:
installer: Package name is Vagrant
installer: Upgrading at base path /
installer: The upgrade was successful.
[otto] Vagrant installed. Cleaning up...
==> Vagrant installed successfully!
==> Creating development environment layers...
    Otto uses layers to speed up building development environments.
    Each layer only needs to be built once. We've detected that the
    layers below aren't created yet. These will be built this time.
    Future development envirionments will use the cached versions
    to be much, much faster.
==> Creating layer: consul
Error building dev environment: Error building dev environment layers: Error executing Vagrant: exit status 1

The error messages from Vagrant are usually very informative.
Please read it carefully and fix any issues it mentions. If
the message isn't clear, please report this to the Otto project.