Release v3.4.0.

Author: kdeldycke

changelog.rst

@@ -2,10 +2,8 @@ Changelog
 =========
 
 
-`3.4.0 (unreleased) <https://github.com/kdeldycke/meta-package-manager/compare/v3.3.0...develop>`_
---------------------------------------------------------------------------------------------------
-
- .. note:: This version is not yet released and is under active development.
+`3.4.0 (2020-08-18) <https://github.com/kdeldycke/meta-package-manager/compare/v3.3.0...v3.4.0>`_
+-------------------------------------------------------------------------------------------------
 
 * [yarn] Set minimal requirement to 1.20.0.
 * [yarn] Fix deprecated global arguments.