Simplify update-versions script with --use-json (#3989)

Author: paulb777

Releases/update-versions.py

@@ -238,10 +238,8 @@ def PushPodspecs(version_data):
       warnings_ok = ''
 
     podspec = '{}.podspec'.format(pod)
-    json = os.path.join(tmp_dir, '{}.json'.format(podspec))
-    LogOrRun('pod ipc spec {} > {}'.format(podspec, json))
-    LogOrRun('pod repo push --skip-tests {} {}{}'.format(GetCpdcInternal(),
-                                                         json, warnings_ok))
+    LogOrRun('pod repo push --skip-tests --use-json {} {}{}'
+             .format(GetCpdcInternal(), podspec, warnings_ok))
   os.system('rm -rf {}'.format(tmp_dir))