post_install(spec, disable_exts = false)public
It builds extensions, generates bins and installs them for the spec provided.
It depends on `spec.loaded_from` to get full_gem_path. The source plugins should set that.
It should be called in `install` after the plugin is done placing the gem at correct install location.
It also runs Gem hooks `pre_install`, `post_build` and `post_install`
Note: Do not override if you don’t know what you are doing.