Initial Honeycomb vagrant support.

Initial Honeycomb vagrant support.

The following environment variables are used to customize
the behavior of the vagrant VM:

HONEYCOMB_VAGRANT_DISTRO
  - Set to "centos7" to run CentOS (currently inop).
    Unset or any other value runs ubuntu 14.04.

HONEYCOMB_M2_REPOSITORY
  - Set to the pathname of a directory to contain the M2 repository
    outside of the VM.  The specified directory will be mounted
    at /m2-repository and /home/vagrant/.m2/settings.xml will be
    modified to use /m2-repository instead of the default
    directory (/home/vagrant/.m2/repository).

VPP_VAGRANT_NICS
  - Set to the number of addtional NICS desired for VPP to use.

VPP_REPO
  - Set to the pathname of a VPP repository.  The specified pathname
    will be mounted on /vpp and a working repo will be cloned into
    /home/vagrant/git/vpp.  VPP will then be built, installed and
    started after the VM is created.

Change-Id: I6b673c3c378c6b6b7c342d91dc33118ecc97bd05
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>