Increase LED saturation to 2019 projected values

[afontani]

Pull Request Description

LED saturation is one of the fastest-changing technologies. Previously, we estimated that the LED saturation was ~10% based on the 2015 U.S. Lighting Market Characterization.

However, LED saturation is projected to be ~27.4% saturation in the residential stock by 2019 in the 2019 Energy Savings Forecast of SolidState Lighting in General Illumination Applications.

This pull request increases the current LED saturation from ~10% to 27.4%.

Checklist

Not all may apply:

• Unit tests have been added or updated
• All rake tasks have been run, and pass
• Documentation has been modified appropriately
• Any new options are added to project_testing
• project_testing runs without any failures
• No unexpected regression test changes
• All tests are passing
• The changelog has been updated appropriately
• This branch is up-to-date with develop

For more information on how to perform these checklist items, see the documentation's Advanced Tutorial.