switch to github stl viewer

[wolfmanjm]

It looks like githubs STL viewer works very well, any chance of using this instead?

https://github.com/blog/1465-stl-file-viewing

[garyhodgson]

Hi @wolfmanjm - it could be a possibility and I will look into it when I get a chance. I'm hoping to put together the next version of the template which will deal with the issue introduced by the recent api changes (see #5).