Update artboards for scrollable content
Set up Jasmine
Extract calculation objects to calculations.js
Write tests for calculations
Update scaling to handle scrollable content

Consider breaking up IPhoneCalculator into separate objects for each
iPhone model.
Update docs for release
Update install instructions
Guard against out of range index values
Add additional debug logging
Fix invalid bounds checking

The recent fix for out of bounds scaling size was incorrectly applied to
the scaling strategy, which is not actually an index, and thus resulted
in the wrong strategy being used.