Pass keep_color: true to shell provisioner

This avoids the confusing combination of red and green messages.

vagrant-spk

@@ -61,9 +61,9 @@ Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
 
   # Use a shell script to "provision" the box. This installs Sandstorm using
   # the bundled installer.
-  config.vm.provision "shell", inline: "sudo bash /opt/app/.sandstorm/global-setup.sh"
+  config.vm.provision "shell", inline: "sudo bash /opt/app/.sandstorm/global-setup.sh", keep_color: true
   # Then, do stack-specific and app-specific setup.
-  config.vm.provision "shell", inline: "sudo bash /opt/app/.sandstorm/setup.sh"
+  config.vm.provision "shell", inline: "sudo bash /opt/app/.sandstorm/setup.sh", keep_color: true
 
   # Shared folders are configured per-provider since vboxsf can't handle >4096 open files,
   # NFS requires privilege escalation every time you bring a VM up,