Install python2 for Ubuntu 16.04 and CentOS 7 in Vagrant

- Fix wrong place to run script in Vagrantfile
- Install python2 for Ubuntu 16.04 and CentOS 7 before executing
  run_tests.sh

Change-Id: I6523d9d6dffcec53ca7511a5735490bd5e0acd27

Vagrantfile

@@ -21,7 +21,7 @@ Vagrant.configure(2) do |config|
     end
     centos7.vm.provision "shell", inline: <<-SHELL
       sudo su -
-      cd /home/vagrant/sync
+      cd /vagrant
       ./run_tests.sh
     SHELL
   end

run_tests.sh

@@ -17,6 +17,16 @@ 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 \