strip all non-essential fields from package.json prior to publishing.

prepublish.js

var path = require('path').join(__dirname, '..', 'package.json');
var pkg = require(path);
['babel', 'greenkeeper', 'bundlesize', 'devDependencies', 'eslintConfig'].forEach(function(key) { delete pkg[key] });
pkg.scripts = { postinstall: pkg.scripts.postinstall, donate: pkg.scripts.donate };
require('fs').writeFileSync(path, JSON.stringify(pkg, null, 2));