debug mode release

[PaulTalbot-INL]

With the merging of #89 there is a new debug option for HERON.

Adding this node to the <Case> node in a HERON input will activate a streamlined run, where nominally a single outer run and limited inner runs will be performed. The number of runs can be controlled by the user.

This streamlined run also outputs the dispatch results directly to the outer working directory, along with plots of the dispatch of the components grouped by resource, to allow clear visualization and debugging how HERON is operating.

Enabling this feature is as simple as adding the <debug> node as follows:

<Case name="my_run_name">
    <mode>sweep</mode>
    <debug>
        <inner_samples>2</inner_samples>
        <macro_steps>2</macro_steps>
        <dispatch_plot>True</dispatch_plot>
    </debug>
    [...]
  </Case>