Add provider.vsphere ip location

[Atadilo]

I use terraform with VSphere provider.

$ terraform version
Terraform v0.11.1
+ provider.vsphere v1.1.1

With terraform-inventory v0.7-pre and my tfstate file, the inventory is empty :

$ terraform-inventory --list terraform.tfstate
{"all":{"hosts":null,"vars":{}}}

In my terraform.tfstate file, the ip address can be found :

"default_ip_address": "x.x.x.x",

[adammck]

Thank you! This is an exemplary PR.