Add Vagrantfile for local testing

Also update run_test.sh to install python2 for Ubuntu 16.04 and CentOS 7
before executing tests

Change-Id: I43ea3e8bce537d514143495b6ba528998cc69169

Vagrantfile

@@ -0,0 +1,8 @@
+Vagrant.configure(2) do |config|
+  config.vm.box = "ubuntu/xenial64"
+  config.vm.provision "shell", inline: <<-SHELL
+      sudo su -
+      cd /vagrant
+      ./run_tests.sh
+    SHELL
+end

run_tests.sh

@@ -17,6 +17,15 @@ set -xeuo pipefail
 
 FUNCTIONAL_TEST=${FUNCTIONAL_TEST:-true}
 
+# Install python2 for Ubuntu 16.04 and CentOS 7
+if which apt-get; then
+    sudo apt-get update && sudo apt-get install -y python
+fi
+
+if which yum; then
+    sudo yum install -y python
+fi
+
 # Install pip.
 if ! which pip; then
   curl --silent --show-error --retry 5 \