[package:vm_service] Bump version to 6.0.1-nullsafety.0 to make pub happy

TEST=None

Change-Id: If0f04c87fb1411084e15460ff9e70cb76498b623
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/180486
Reviewed-by: Gary Roumanis <grouma@google.com>
diff --git a/pkg/vm_service/CHANGELOG.md b/pkg/vm_service/CHANGELOG.md
index 3b25e2f..4bd758c 100644
--- a/pkg/vm_service/CHANGELOG.md
+++ b/pkg/vm_service/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+## 6.0.1-nullsafety.0
+- Fix versioning for pub.
+
 ## 6.0.0-nullsafety.4
 - Fixed issue where response parsing could fail for `SourceReportRange.coverage`
   if no coverage information was provided.
diff --git a/pkg/vm_service/pubspec.yaml b/pkg/vm_service/pubspec.yaml
index 3ef0b3f..fc44e80 100644
--- a/pkg/vm_service/pubspec.yaml
+++ b/pkg/vm_service/pubspec.yaml
@@ -3,7 +3,7 @@
   A library to communicate with a service implementing the Dart VM
   service protocol.
 
-version: 6.0.0-nullsafety.4
+version: 6.0.1-nullsafety.0
 
 homepage: https://github.com/dart-lang/sdk/tree/master/pkg/vm_service