MQE-2206: CHANGELOG.MD and Composer version bump

fixed error in 2.6.3, 2.6.4 changelog

Author: soumyau

CHANGELOG.md

@@ -88,12 +88,15 @@ Magento Functional Testing Framework Changelog
 * [MFTF 3.0.0 RC2](https://www.youtube.com/watch?v=BJOQAw6dX5o)
 * [MFTF 3.0.0 RC3](https://www.youtube.com/watch?v=scLb7pi8pR0)
 
-2.6.3
+2.6.4
 -----
 
 ### Fixes
 * added dependency to packages MFTF used but never specified in composer.json
 
+2.6.3
+-----
+
 ### New Feature
 * `--filter` option was added to `bin/mftf generate:tests` command. For more details please go to https://devdocs.magento.com/mftf/docs/commands/mftf.html#generatetests