Added AWS_REGION to the documentation of our settings

docs/settingsvariables.rst

@@ -81,12 +81,23 @@ AWS_SECRET_ACCESS_KEY
 
     AWS_SECRET_ACCESS_KEY = 'your-secret-key'
 
+AWS_REGION
+----------
+
+.. envvar:: AWS_REGION
+
+    The name of the Amazon Web Services' region where the S3 bucket is stored. Results depend on the endpoint and region, but if you are not using the default ``us-east-1`` region you may need to set this variable.
+
+.. code-block::
+
+    AWS_REGION = 'us-west-2'
+
 AWS_S3_ENDPOINT
 -----------
 
 .. envvar:: AWS_S3_ENDPOINT
 
-    The URL to use when connecting with Amazon Web Service's S3 system. If the
+    The URL to use when connecting with Amazon Web Services' S3 system. If the
     setting is not provided the boto package's default is used.
 
 .. code-block:: python