private Task ArchiveInvocation(IOrderedEnumerable<InvocationState.InvocationRow> invocationHistory)
{
var latest = invocationHistory.Last();
string name = String.Format(
"{0}_{1}_{2}.json",
latest.Job,
latest.UpdatedAt.ToString("s"),
latest.Id.ToString("N").ToLowerInvariant());
return _archiveContainer.UploadJsonBlob(name, invocationHistory.ToArray());
}