Install python2 for Ubuntu 16.04 and CentOS 7 in Vagrant

- Handle apt-get update in run_tests.sh
- Install python2 for Ubuntu 16.04 and CentOS 7 before executing test
  script.

Change-Id: I439934a463858f46647d8b00467076fbf8f12416

Vagrantfile

@@ -19,7 +19,6 @@ Vagrant.configure(2) do |config|
   config.vm.provision "bootstrap", type: "shell", inline: <<-SHELL
     sudo su -
     cd /vagrant
-    apt-get update
     FUNCTIONAL_TEST=false ./run_tests.sh
   SHELL
   # Run functional tests

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 \