Specify Vagrant box version

Add a line which states the version of the Vagrant box to be used when
provisioning a development environment.

NB: In this case, 0.2.0 is an image based on CentOS 7.5

Change-Id: I81613df1d20dfd1b99a5d7624fc1627ca185dd7f
Story: 2002086
Task: 19755

Vagrantfile

@@ -7,6 +7,7 @@ Vagrant.configure('2') do |config|
   config.vm.network 'private_network', ip: '192.168.33.3', auto_config: false
 
   config.vm.box = 'stackhpc/centos-7'
+  config.vm.box_version = '0.2.0'
 
   config.vm.provider 'virtualbox' do |vb|
     vb.memory = '4096'