Demo: add directional light

[Shimuuar]

Demo only uses ambient light so all faces are are illuminated equally and so have identical color. Picture will look much nicer if directional light is added to scene. It's even more important in more complicated geometries.

Note. Not all materials interact correctly with directed light (MeshStandardMaterial does)

[altavir]

Fixed in 0.2.1. Lights are added as objects instead of scene options.