we want to allow config precedence over ssh settings. other than host, the ssh settings will not apply to winrm

I was testing the latest Transform on Hyper-V and VirtualBox tonight and found a problem with Hyper-V. Since all settings are fed from vagrant ssh-config, most were wrong for my box. I use a different username and password than 'vagrant'  and they were not being used and kitchen was trying to talk to winrm on port 22 since that is indeed the port that shows up in ssh-config. We dont see this problem on VirtualBox since it uses a different strategy for getting the port and in my case I do use the standard vagrant user on my virtualbox box but its certainly possible someone else could use a different user.

This was throwing:
```
STDERR: Renaming the Windows guest failed. Most often this is because you've
specified a FQDN instead of just a host name.
```
Now rather than delete it, I'll change this to match @jdmundrawala PR which changes this to:
```
default_config :box do |driver|
  "opscode-#{driver.instance.platform.name}"
end
```
and this works fine.