Adjust timestamps in test_psm3.csv

[cwhanse]

• Closes Update test_psm3.csv #733
• I am familiar with the contributing guidelines.
• Fully tested. Added and/or modified tests to ensure correct behavior for all reasonable inputs. Tests (usually) must pass on the TravisCI and Appveyor testing services.
• Adds description and name entries in the appropriate docs/sphinx/source/whatsnew file for all changes.
• Code quality and style is sufficient. Passes LGTM and SticklerCI checks.
• New code is fully documented. Includes sphinx/numpydoc compliant docstrings and comments in the code where necessary.
• Pull request is nearly complete and ready for detailed review.

Brief description of the problem and proposed solution (if not already fully described in the issue linked to above): NSRDB change in 6/2019 move timestamps to the midpoint of each hour, e.g., 1230 for the hour between 1200 and 1300. This change adjusts the timestamps in the fixed data file test_psm3.csv.

[mikofski]

Thanks!

[wholmgren]

@cwhanse merge if ready.