Update changelog for 0.22

Author: julien-duponchelle

CHANGELOG

@@ -141,3 +141,6 @@
 * fix ci configuration
 * Added support for limited columnar access in MySQL
 
+0.22 20/09/2020
+* Support PyMysql with a version greater than 0.9.3
+* Fix handling of JSON literal values

README.md

@@ -324,6 +324,8 @@ Other contributors:
 * Keegan Parker: secondary database for reference schema https://github.com/kdparker
 * Troy J. Farrell Clear table_map if RotateEvent has timestamp of 0 https://github.com/troyjfarrell
 * Zhanwei Wang Fail to get table informations https://github.com/wangzw
+* Alexander Ignatov Fix the JSON literal 
+* Garen Chan Support PyMysql with a version greater than 0.9.3  https://github.com/garenchan
 
 Thanks to GetResponse for their support