Update CHANGELOG

Signed-off-by: jojohappy <sarahdj0917@gmail.com>

CHANGELOG.md

@@ -10,18 +10,9 @@ NOTE: As semantic versioning states all 0.y.z releases can contain breaking chan
 We use *breaking* word for marking changes that are not backward compatible (relates only to v0.y.z releases.)
 
 ## Unreleased
-## [v0.4.0](https://github.com/improbable-eng/thanos/releases/tag/v0.4.0) - 2019.05.3
-### Added
-
-- [#1060](https://github.com/improbable-eng/thanos/pull/1060) Allow specifying region attribute in S3 storage configuration
-
-### Fixed
-
-- [#1070](https://github.com/improbable-eng/thanos/pull/1070) Downsampling works back again. Deferred closer errors are now properly captured.
 
 ### Changed
 
-- [#1073](https://github.com/improbable-eng/thanos/pull/1073) Store: index cache for requests. It now calculates the size properly (includes slice header), has anti-deadlock safeguard and reports more metrics.
 - [#1066](https://github.com/improbable-eng/thanos/pull/1066) Upgrade Thanos ui to Prometheus v2.9.1.
 
   Changes from the upstream:
@@ -35,7 +26,7 @@ We use *breaking* word for marking changes that are not backward compatible (rel
     - [ENHANCEMENT] Improve rule views by wrapping lines [PR #4702](https://github.com/prometheus/prometheus/pull/4702)
     - [ENHANCEMENT] Show rule evaluation errors on rules page [PR #4457](https://github.com/prometheus/prometheus/pull/4457)
 
-## [v0.4.0-rc.0](https://github.com/improbable-eng/thanos/releases/tag/v0.4.0-rc.0) - 2019.04.18
+## [v0.4.0](https://github.com/improbable-eng/thanos/releases/tag/v0.4.0) - 2019.05.3
 
 :warning: **IMPORTANT** :warning: This is the last release that supports gossip. From Thanos v0.5.0, gossip will be completely removed.