Replace gpu.js with tensorflowjs

[hiukim]

In view of having lots of unknown bugs from gpu.js, I'm trying to replace it with another library for the webgl part.

I came up with this interesting idea of using tensorflow while discussing with my colleague. There is a very solid foundation of of api that utilize webgl in tensorflow, so I decided to give it a try. Nope, we are not using it for Machine Learning. :D

If it works out, it will solve most of the issues.

[kalwalt]

Great news @hiukim ! 🙂👍🤸