Bump version to 4.31.2 and update changelog

Author: rmk135

docs/main/changelog.rst

@@ -7,11 +7,14 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
-Development version
--------------------
+4.31.2
+------
 - Fix an issue with ``Dict`` provider non-string keys.
   See issue: `#435 <https://github.com/ets-labs/python-dependency-injector/issues/435>`_.
   Thanks to `@daniel55411 <https://github.com/daniel55411>`_ for reporting the issue.
+- Fix Flask scoped contexts example.
+  See issue: `#440 <https://github.com/ets-labs/python-dependency-injector/pull/440>`_.
+  Thanks to `@sonthonaxrk <https://github.com/sonthonaxrk>`_ for the contribution.
 
 4.31.1
 ------

src/dependency_injector/__init__.py

@@ -1,6 +1,6 @@
 """Top-level package."""
 
-__version__ = '4.31.1'
+__version__ = '4.31.2'
 """Version number.
 
 :type: str