Unconventional name for the "input provider" option

[xicesky]

A rather minor issue: Usually options with multiple words are seperated by dashes, not by underscore - if you get it wrong, vagrant mutate also does not give u a very helpful error message:

vagrant mutate debian-7.8.0-amd64 libvirt --input-provider=virtualbox
An invalid option was specified. The help for this command
is available below.

Of course the command should be --input_provider=virtualbox
A more helpful error message would be "invalid option: --input-provider".

[sciurus]

The error message "An invalid option was specified. The help for this command is available below." is generated by vagrant itself, not vagrant-mutate.

I see your point about the underscore. I'm open to changing that if you'd like to submit a PR.

[xicesky]

I'm not really into ruby, but i'll see what i can do. Sound like a faily minor change.