Updated from OpenStack Ansible Tests

Change-Id: If5415f3ea9a311dc7ca9163e075fe2493ed46283

Vagrantfile

@@ -1,16 +1,31 @@
+# Verify whether required plugins are installed.
+required_plugins = [ "vagrant-disksize" ]
+required_plugins.each do |plugin|
+  if not Vagrant.has_plugin?(plugin)
+    raise "The vagrant plugin #{plugin} is required. Please run `vagrant plugin install #{plugin}`"
+  end
+end
+
 Vagrant.configure(2) do |config|
   config.vm.provider "virtualbox" do |v|
     v.memory = 2048
     v.cpus = 2
   end
 
+  config.vm.provision "shell",
+      privileged: false,
+      inline: <<-SHELL
+          cd /vagrant
+         ./run_tests.sh
+      SHELL
+
   config.vm.define "ubuntu1604" do |xenial|
+    xenial.disksize.size = "40GB"
     xenial.vm.box = "ubuntu/xenial64"
-    xenial.vm.provision "shell", inline: <<-SHELL
-      sudo su -
-      cd /vagrant
-      apt-get update
-      ./run_tests.sh
-    SHELL
   end
+
+  config.vm.define "centos7" do |centos7|
+    centos7.vm.box = "centos/7"
+  end
+
 end