Adjustments for canvas mock

[Downchuck]

I've been trying to use https://github.com/Adamfsk/jest-webgl-canvas-mock to setup an automated test. I may have initialized ngl incorrectly as I am using code that targeted 0.10.

These two items were where I had to insert a return statement, as their objects were not set on this and so they resulted in an undefined error.

The LineSegments and AnimationControl objects will not set correctly so on load, there's an error in Stage.prototype.autoView as this.animationControls is not present, and Viewer.prototype.updateHelper does not have this.boundingBoxMesh.

[arose]

as their objects were not set on this and so they resulted in an undefined error.

can you please elaborate