Update version field to 1.3.1

Hanzhang Zeng (Roger) · Hanzhang Zeng (Roger) · commit 03ddadfd4ff9 · 2020-09-08T11:01:08.000-07:00
diff --git a/azure/functions/__init__.py b/azure/functions/__init__.py
@@ -55,4 +55,4 @@
     'WsgiMiddleware'
 )
 
-__version__ = '1.3.0'
+__version__ = '1.3.1'
