[Network] Traffic-manager endpoint create fails with minimum required parameters

When supplying only the minimum required parameters with, an error is raised:
`Please specify properties for endpoint 'ep1'`

This is the error that comes back from the server. It would be very helpful if it returned **which** properties should be set, especially since different profile/endpoint configurations require different properties to be set.

In this case, the routing method of the profile is 'performance' and I get this very unhelpful, generic error regardless of the endpoint type I specify.