Bump version to 4.20.2

Author: rmk135

docs/main/changelog.rst

@@ -7,6 +7,10 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
+4.20.2
+------
+- Move docs on container "self" injections to "Providers" section.
+
 4.20.1
 ------
 - Refactor containers module.

src/dependency_injector/__init__.py

@@ -1,6 +1,6 @@
 """Top-level package."""
 
-__version__ = '4.20.1'
+__version__ = '4.20.2'
 """Version number.
 
 :type: str