Version 0.15.0

2020-01-18

Added

• Support for the KHR_materials_unlit extension, which adds an unlit field
  to Material.
• ExactSizeIterator implementations for accessor iterators.

Fixed

• Some lifetimes for accessing fields (e.g. Node::children) have been relaxed.
• Accessor::buffer_view is now optional for the benefit of sparse accessors.

Removed

• animation::Interpolation::CatmullRomSpline