title: How to reset luigi task status?
body: <p>Currently, I have a bunch of luigi tasks queued together, with a simple dependency chain( <code>a -&gt; b -&gt; c -&gt; d</code>). <code>d</code> gets executed first, and <code>a</code> at the end. <code>a</code> is the task that gets triggered. </p>
  
  <p>All the targets except <code>a</code> return a <code>luigi.LocalTarget()</code> object and have a single generic <code>luigi.Parameter()</code> which is a string (containing a date and a time). Runs on a luigi central server (which has history enabled).</p>
  
  <p>The problem is that, when I rerun the said task <code>a</code>, luigi checks the history and sees if that particular task has been run before, if it had had a status of DONE, it doesn't run the tasks (<code>d</code> in this case) and I can't have that, changing the string isn't helping (added a random microsecond to it). How do I force run a task ?</p>