[Debian-science-sagemath] Consider updating package three.js

[jose]

Please consider upgrading three.js to a more recent version. When trying 
to use plot3d I get only axes drawn (or even a black image), either in 
testing or unstable (not tried stable).

Failing code is:

x, y = var('x y')

plot3d(x*x+y*y, (-3,3), (-3,3))

But this works
plot3d(x*x+y*y, (-3,3), (-3,3), viewer='tachyon')

In debug console I can see:

THREE.WebGLRenderer 80 three.min.js:12:4970
THREE.WebGLRenderer: ANGLE_instanced_arrays extension not supported. 
three.min.js:11:3290
THREE.MeshPhongMaterial: 'flatShading' is not a property of this 
material. three.min.js:4:12201

PS: Sorry for not reporting as bug, never filed one and learning curve 
seems steep.