Do not specify config.servicemanager.services in per user Vagrantfile

In chapter 3.4.2. Using vagrant-service-manager to Set Proxy Environment Variables of doc-Container_Development_Kit-Installation_Guide-branch-master (docs) user should edit per user Vagrant file to setup proxy environment. For proxy, proxy_user and proxy_password this makes sense as most users will be using one proxy for both OpenShift and Kubernetes.

I see problem with line >> config.servicemanager.services = '<orchestration service>, docker' <<. As user specifies here if he is going to use OpenShift or Kubernetes. When she wants to switch from one to another, she needs to edit per user Vagrantfile. It would be better to add this line to Vagrantfile in /rhel/rhel-ose or /rhel/misc/rhel-k8s-singlenode-setup. As there is need to edit these files by deleting some lines already, it is not complicating setup for user.

With this update, user can switch between OSE and Kubernetes without editing per user Vagrant file.

Tested this on RHEL 7.3 workstation and it is working.