Bring Redhat support to acceptance tests

OpenStack Infra has jobs to run this on both Ubuntu Trusty and CentOS7.

* Add minitest to Gemfile (dependency to run beaker on centos - see
  http://projects.theforeman.org/issues/2650 for details)
* separate nodepool files to have trusty & centos7 support in OS infra

Change-Id: I3470c38ac7598d4444dd79d9e7642d9321ff7fc6
Closes-bug: #1444736

Gemfile

@@ -1,6 +1,7 @@
 source 'https://rubygems.org'
 
 group :development, :test do
+  gem 'minitest', '~> 4.7', :require => 'minitest/unit'
   gem 'puppetlabs_spec_helper', :require => false
   gem 'rspec-puppet', '~> 2.1.0', :require => false
 

spec/acceptance/nodesets/nodepool-centos7.yml

@@ -0,0 +1,9 @@
+HOSTS:
+  centos-70-x64:
+    roles:
+      - master
+    platform: el-7-x86_64
+    hypervisor : none
+    ip: 127.0.0.1
+CONFIG:
+  type: foss