build/lib/util.ts/cleanNodeModules
export function cleanNodeModules(rulePath: string): NodeJS.ReadWriteStream {
	const rules = fs.readFileSync(rulePath, 'utf8')
		.split(/\r?\n/g)
		.map(line => line.trim())
		.filter(line => line && !/^#/.test(line));

	const excludes = rules.filter(line => !/^!/.test(line)).map(line => `!**/node_modules/${line}`);
	const includes = rules.filter(line => /^!/.test(line)).map(line => `**/node_modules/${line.substr(1)}`);

	const input = es.through();
	const output = es.merge(
		input.pipe(_filter(['**', ...excludes])),
		input.pipe(_filter(includes))
	);

	return es.duplex(input, output);
}