chore: prepare v9.0.1 for release

Author: Justintime50

Diff for: easypost/constant.py

@@ -1,6 +1,6 @@
 # flake8: noqa
 # Library version
-VERSION = "9.0.0"
+VERSION = "9.0.1"
 VERSION_INFO = [str(number) for number in VERSION.split(".")]
 
 # Client defaults

Diff for: setup.py

@@ -31,7 +31,7 @@
 
 setup(
     name="easypost",
-    version="9.0.0",
+    version="9.0.1",
     description="EasyPost Shipping API Client Library for Python",
     author="EasyPost",
     author_email="support@easypost.com",