Update versions in the docs

Author: rmk135

docs/introduction/installation.rst

@@ -23,7 +23,7 @@ To verify the installed version:
 
     >>> import dependency_injector
     >>> dependency_injector.__version__
-    '4.0.0'
+    '4.37.0'
 
 .. note::
     When add ``Dependency Injector`` to the ``requirements.txt`` don't forget to pin version

docs/tutorials/flask.rst

@@ -110,7 +110,7 @@ You should see something like:
 .. code-block:: bash
 
    (venv) $ python -c "import dependency_injector; print(dependency_injector.__version__)"
-   4.0.0
+   4.37.0
    (venv) $ python -c "import flask; print(flask.__version__)"
    1.1.2