in src/main/scala/com/gu/ssm/IO.scala [46:50]
def executeOnInstanceAsync(instanceId: InstanceId, username: String, script: String, client: AWSSimpleSystemsManagementAsync)(implicit ec: ExecutionContext): Attempt[String] = {
for {
cmdId <- SSM.sendCommand(List(instanceId), script, username, client)
} yield cmdId
}