[CORD-2463]
Make box used by Vagrant VM's a parameter

Change-Id: I19437de9126146a4e102b6db3288e6ae73b1354a
diff --git a/scenarios/single/config.yml b/scenarios/single/config.yml
index b32035e..4bf4450 100644
--- a/scenarios/single/config.yml
+++ b/scenarios/single/config.yml
@@ -25,6 +25,7 @@
 build_cord_dir: /opt/cord
 
 # Vagrant VM configuration
+vagrant_box: "ubuntu/trusty64"
 head_vm_mem: 4096
 head_vm_cpu: 8
 head_vm_ip: "192.168.46.100"