publish path fix

Author: JoshuaMiller

Jenkins.Net.Publishing/Scripts/Publish.cs

@@ -23,7 +23,7 @@ public async Task RunAsync(CancellationToken token)
             };
             nugetCore.Initialize();
 
-            var packageDir = Path.Combine(Context.ContentDirectory, "PublishPackage");
+            var packageDir = Path.Combine(Context.BinDirectory, "PublishPackage");
 
             var packageFilename = Directory
                 .GetFiles(packageDir, "jenkinsnet.*.nupkg")