Add pug/jade global helpers

gulpfile.js

gulp.task('pug', function () {
	global._ = require('lodash');
	global.helpers = require('./' + paths.src.root + '/pug-helpers');
	global.mocks = require('./' + paths.dest.root + '/mocks.json');

	return gulp.src(paths.src.html + '/**/!(_)*.pug')
		.pipe(plumber())
		.pipe(pug({
			doctype: 'html',
			pretty: true,
			globals: ['_', 'helpers', 'mocks'],
		}))
		.pipe(gulp.dest(paths.dest.html));
});