Introduce role-based serverspec testing, powered by everybody's favorite hobo

This allows for writing and running acceptance tests for specific roles
(dist/role/manifests/*.pp) and spinning up a Vagrant AWS machine with that
role, then running the appropriate serverspec tests against it.
Add a placeholder spec dir for artichoke aka puppetmaster
Merge pull request #25 from rtyler/vagrant-serverspec-and-roles

Introduce role-based serverspec testing, powered by Vagrant
Adding a script to edit common.yaml

... so that I won't forget how to do it.
Document the local vagrant-based testing workflow
Fix the relative link to roles
Fix the relative link to roles, really
Set the box URL so that it doesn't have to be installed separately
Adding the check to verify required plugins are available
Added manifest to install and run robobutler
Fix the `lint` rake task to use the right `ignore_paths`

Otherwise, a local `r10k puppetfile install` would cause boatloads of lint
errors since the puppetlabs_spec_helper lint task overwrites ignore_paths
instead of adding to it
(https://github.com/jenkins-infra/puppetlabs_spec_helper/blob/master/lib/puppetlabs_spec_helper/rake_tasks.rb#L162)
Upgrade the Vagrantfile to use a Docker-capable 12.04 LTS AMI
Add vagrant/test-environment specific hiera data
Refactor the main docker management into the docker profile

This should be included by all profiles that need to use docker
update butlerbot profile and add more test coverage
Rework the butlerbot profile to use the puppetlabs/apache modules apache::vhost type
Remove the jenkins_apache module from the tree, this exists in puppet-apache-logcompressor
Add the puppet-apache-logcompressor module

This commit also reorganizes the .fixtures.yml file a bit to include more
modules that can be found directly on forge. It's a bit faster than a full git
clone
Incorporate the log-compressor module into the robobutler profile