If you try to use newer stdweb, running the example gives errors of the form:

LinkError: import object field '__js_uniform4vf' is not a Function

You can avoid the problem by adding = in the Cargo.toml of uni-pad:

stdweb =  "=0.4.8"

It seems there is no problem with stdweb 0.4.10 but stdweb 0.4.11 is broken.