bugfix 1872 plot_tcmpr.R -lookin directory (main_v10.0)

[georgemccabe]

Pull Request Testing

• Describe testing already performed for these changes:
  

Ran a use case on Hera and confirmed that the script is able to run as expected.

• Recommend testing for the reviewer(s) to perform, including the location of input datasets, and any additional instructions:
  

None needed, this is a very simple fix. If desired, you can test calling the plotter passing in a directory that contains .tcst files with the -lookin argument. It should fail without this fix.

• Do these changes include sufficient documentation updates, ensuring that no errors or warnings exist in the build of the documentation? [Yes]

• Do these changes include sufficient testing updates? [Yes]

• Will this PR result in changes to the test suite? [No]
  

• Please complete this pull request review by 8/20/2021.
  

Pull Request Checklist

See the METplus Workflow for details.

• Complete the PR definition above.
• Ensure the PR title matches the feature or bugfix branch name.
• Define the PR metadata, as permissions allow.
  Select: Reviewer(s)
  Select: Organization level software support Project or Repository level development cycle Project
  Select: Milestone as the version that will include these changes
• After submitting the PR, select Linked issues with the original issue number.
• After the PR is approved, merge your changes. If permissions do not allow this, request that the reviewer do the merge.
• Close the linked issue and delete your feature or bugfix branch from GitHub.

[JohnHalleyGotway]

I approve of this simple change, updating the plot_tcmpr.R script to change "ls -1" to "ls -1d".