Add types to uniforms

[Sebastian Sanabria Diaz]

When calling addUniform, the value is always a f32, this would be a lot better if the values could be more than that, like i32, vec2, etc.

let val = 6.7;
addUniform(val) //default f32

let val = [0.,0.]
addUniform(val, 'vec2');

[Sebastian Sanabria Diaz]

This has been addressed with PR #86