The currently used client (boto3==1.9.139) is outdated and does not support ECS Fargate 1.4 style tasks with EFS volume configuration:
<span>✖ ECS task definition parameter validation error: </span><span>Parameter validation failed:</span><span>Unknown parameter in volumes[0]: "efsVolumeConfiguration", must be one of: name, host, dockerVolumeConfiguration<br><br></span>
<span>boto3 1.13.3 would be ok.</span>