7.1 remove old autorest (#785)

* init removal

* clean up warning

* bump ver to 7.1

* fix build

* custom http client no long supported

* cleanup unused types

* fix npe

* remove service client

* modern ssl settings

* fix test

* fix client cert null

* fix ctor

* cleanup

examples/watch/Program.cs

@@ -3,7 +3,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using k8s;
 using k8s.Models;
-using Microsoft.Rest;
+using k8s.Autorest;
 
 namespace watch
 {