remove simplejson requirement

The json lib has been included in CPython for
ages, so the ImportError case never happens.

Change-Id: I669bc397323a0e83d4a9768b124a7d99bafaf38a

cinderclient/client.py

@@ -20,6 +20,7 @@ import glob
 import hashlib
 import importlib.util
 import itertools
+import json
 import logging
 import os
 import pkgutil
@@ -46,11 +47,6 @@ try:
 except ImportError:
     from time import sleep
 
-try:
-    import json
-except ImportError:
-    import simplejson as json
-
 try:
     osprofiler_web = importutils.try_import("osprofiler.web")
 except Exception:

requirements.txt

@@ -4,7 +4,6 @@
 pbr>=5.5.0 # Apache-2.0
 PrettyTable>=0.7.2 # BSD
 keystoneauth1>=4.3.1 # Apache-2.0
-simplejson>=3.5.1 # MIT
 oslo.i18n>=5.0.1 # Apache-2.0
 oslo.utils>=4.8.0 # Apache-2.0
 requests>=2.25.1 # Apache-2.0