Schedule file interpolation bugfix

[shorowit]

Pull Request Description

Bugfix for when a detailed schedule is used with higher resolution (e.g., 10-min data) than the simulation timestep (e.g., 60-min). Previously it would use the instantaneous schedule value that occurred at the beginning of each hour, now it will interpolate.

Example of results before:

And after:

Checklist

Not all may apply:

• Schematron validator (EPvalidator.xml) has been updated
• Sample files have been added/updated (openstudio tasks.rb update_hpxmls)
• Tests have been added/updated (e.g., HPXMLtoOpenStudio/tests/test*.rb and/or workflow/tests/test*.rb)
• Documentation has been updated
• Changelog has been updated
• openstudio tasks.rb update_measures has been run
• No unexpected changes to simulation results of sample files

[shorowit]

I compared the schedule csv full load hours to the simulation output full load hours for some random end uses, for the master branch and this branch.

	lighting_interior	cooking_range	dishwasher	plug_loads_tv
sched data	2077	534	213	1505
outputs before	2063	581	216	1490
outputs after	2076	534	213	1506

The results in this branch are clearly better. I think that's enough validation that this is correct.