Check the app veyor tag for nuget publish

Author: mvput

build.cake

@@ -209,7 +209,7 @@ Task("PublishMyGet")
 });
 
 Task("PublishNuGet")
-    .WithCriteria(() => buildParameters.ShouldPublishNuGet)
+    .WithCriteria(() => buildParameters.ShouldPublishNuGet && !string.IsNullOrWhiteSpace("APPVEYOR_REPO_TAG_NAME"))
     .IsDependentOn("Pack")
     .Does(() =>
 {
@@ -330,4 +330,4 @@ public class BuildParameters
         .Append("/p:AssemblyVersion={0}", GitVersion.MajorMinorPatch)
         .Append("/p:FileVersion={0}", GitVersion.MajorMinorPatch)
         .Append("/p:AssemblyInformationalVersion={0}", GitVersion.InformationalVersion);
-}
+}