align auth provider with go-client (#1415)

* remove unsupport provider

* fix build

* fix missing

* rm unused

tests/KubernetesClient.Tests/GcpTokenProviderTests.cs

@@ -1,28 +0,0 @@
-using FluentAssertions;
-using k8s.Authentication;
-using System;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace k8s.Tests
-{
-    public class GcpTokenProviderTests
-    {
-        [OperatingSystemDependentFact(Exclude = OperatingSystems.OSX)]
-        public async Task GetToken()
-        {
-            var isWindows = Environment.OSVersion.Platform == PlatformID.Win32NT;
-            var cmd = Path.Combine(Directory.GetCurrentDirectory(), "assets", isWindows ? "mock-gcloud.cmd" : "mock-gcloud.sh");
-            if (!isWindows)
-            {
-                System.Diagnostics.Process.Start("chmod", $"+x {cmd}").WaitForExit();
-            }
-
-            var sut = new GcpTokenProvider(cmd);
-            var result = await sut.GetAuthenticationHeaderAsync(CancellationToken.None).ConfigureAwait(false);
-            result.Scheme.Should().Be("Bearer");
-            result.Parameter.Should().Be("ACCESS-TOKEN");
-        }
-    }
-}