Create a cell

The following is an example of a request to create a cell, and the response.

aws route53-recovery-readiness --region us-west-2 create-cell \
			--cell-name test-cell

{
    "CellArn": "arn:aws:route53-recovery-readiness::888888888888:cell/test-cell",
    "CellName": "test-cell",
    "Cells": [],
    "ParentReadinessScopes": [],
    "Tags": {}
}