Update CHANGELOG

CHANGELOG.md

@@ -5,7 +5,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [1.2.0-beta] - Unreleased
+## [1.2.0-beta] - 2020-12-15
 
 ### Added
 
@@ -23,14 +23,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - PATCH requests from cvat-core submit only changed fields (<https://github.com/openvinotoolkit/cvat/pull/2445>)
 - Migrated to Antd 4.9 (<https://github.com/openvinotoolkit/cvat/pull/2536>)
 
-### Deprecated
-
--
-
-### Removed
-
--
-
 ### Fixed
 
 - Django templates for email and user guide (<https://github.com/openvinotoolkit/cvat/pull/2412>)
@@ -49,10 +41,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Reset state (reviews, issues) after logout or changing a job (<https://github.com/openvinotoolkit/cvat/pull/2525>)
 - TypeError: Cannot read property 'id' of undefined when updating a task (<https://github.com/openvinotoolkit/cvat/pull/2544>)
 
-### Security
-
--
-
 ## [1.2.0-alpha] - 2020-11-09
 
 ### Added