Add change log for 0.5.1 release

Author: Jiawei0227

CHANGELOG-0.5.md

@@ -1,3 +1,29 @@
+# Release notes for v0.5.1
+
+[Documentation](https://docs.k8s.io/docs/home)
+# Changelog since v0.5.0
+
+## Changes by Kind
+
+### Feature
+
+### Uncategorized
+
+- release-0.5: update release-tools ([#110](https://github.com/kubernetes-csi/external-resizer/pull/75), [@Jiawei0227](https://github.com/Jiawei0227))
+  - Build with Go 1.15
+## Dependencies
+
+### Added
+_Nothing has changed._
+
+### Changed
+- github.com/kubernetes-csi/csi-lib-utils: [v0.7.0 → v0.7.1](https://github.com/kubernetes-csi/csi-lib-utils/compare/v0.7.0...v0.7.1)
+
+### Removed
+_Nothing has changed._
+
+# Release notes for v0.5.0
+
 # Changelog since v0.4.0
 
 ## New Features