v4.0.0

Changes

• package.json:bin now points to a different file than package.json:main. This means that doing require('postinstall-build'), while never officially supported, no longer runs the postinstall-build script (instead, it exports the function that runs it). This is to protect against misbehaving dependencies that may import modules they happen to find under node_modules and expect there to be no side effects. See #18.