Use closure compiler from npm in build.js

[vbfox]

This use the script npm generate in .bin inside build.js so that the version align and a global install isn't necessary.

[stanley-cheung]

I am not entirely sure about this. What's the difference between doing it this way __dirname, "../node_modules/.bin vs npx google-closure-compiler?

[vbfox]

If the current directory contains the node_modules folder (or is a subdirectory) there is no difference, npx will essentially find the same file specified here in .bin and run it.

Accessing it directly only changes the behavior if the current directory is somewhere else (npx will get the latest version from npm)

In the end it's you choice there is not much difference (A little bit more security on what version is resolved that's all)

[stanley-cheung]

Thanks for the contribution!