Add new file

update_task_definition_image.py

+import sys, json, argparse
+
+parser = argparse.ArgumentParser('Replaces image in the task definition')
+parser.add_argument('image_uri', metavar='I', type=str, nargs='+',
+                   help='The new image URI')
+
+args = parser.parse_args()
+
+definition = json.load(sys.stdin)['taskDefinition']['containerDefinitions']
+definition[0]['image'] = args.image_uri[0]
+print json.dumps(definition)
\ No newline at end of file