Updated token auth to allow for UPN usernames and Hypervisor based auth

[callumslab]

Hi,

Thanks for the great module!

I've come to use it in our environment and I was having issues authenticating due to the fact we can only use UPN based usernames.

I noticed that you specifically defined a "domain\username" format when authenticating so I've made this more generic.

It should now support the following username formats:
username
domain\username
username@domain.com

I've also added a switch parameter named "HypervisorAuth" to be used when authenticating with Hypervisor based credentials i.e. non Windows based such as vSphere or Hyper-V.

The reason for this is described at step 7 here in Zerto's API documentation:
http://s3.amazonaws.com/zertodownload_docs/5.0U2/Zerto%20Virtual%20Replication%20REST%20APIs%20Online%20Help/index.html#page/Zerto_Virtual_Replication_REST_APIs%2FAPIs_Cmdlets.3.2.html%23

If you are authenticating with the default, Windows credentials, remove “-Body $body -ContentType $contentType”

Thanks,
Callum