Full Vagrant provider. Squashed commits
Fixed Flake8 errors
Silence the McCabe checker on two methods, refs #276.
Updated Berksfile format for 3.0.0 beta 3 and Chef to 11.6.2.
Started on docs
Changed sync_folder path in Vagrantfile.local.example to mount parent path
Added missing warning to vagrant provisioning script.
Experimenting with using hostname rather than IP to SSH into host.
User needs ot have avahi-daemon installed though. Also trying to
update the Chef Server with the Deis Controller's 192 range IP so
that rsyslog has the correct IP.

Conflicts:
	Berksfile.lock
	Gemfile.lock
1) Use private network and static IPs for all vagrant VMs. 2) Use
'knife edit' in provision script to override the ipaddress for the
Controller so that subseuent nodes have the correct rsyslog server
address. 3) Use hostname of the host machine to connect to it over SSH
form the Controller, this gets around IP address changes. But it means
use must have avahi-daemon running.
Override rsyslog behaviour by using Vagrantfile to create a higher
priority conf file. This allows rsyslog clients to communicate with
the rsyslog server on the on the Controller.
If CM's purge_node() fails then raise an error.
Instructions to add Controller to Chef's admin group and note to install avahi-daemon/Bonjour
Merge branch '232-vagrant-provider-full' of https://github.com/tombh/deis into tombh-232-vagrant-provider-full
Updated docs and only test for avahi-daemon on Linux.