Copy main soure from dependencies

copy.js

	grunt.task.registerTask('copy-deps', 'Copy npm dependencies', function () {
	    var done = this.async();
	    var deps = Object.keys(pkg.dependencies);

	    var path = require('path');
	    var fs = require('fs');

	    if ( deps.length ) {
	    	deps.forEach((dep) => {

	    		var depDir = path.join(__dirname, 'node_modules', dep);
	    		var depPkg = require(path.join(depDir, 'package.json'));

	    		if ( depPkg.main ) {
	    			fs.createReadStream( path.join(depDir, depPkg.main )).pipe(fs.createWriteStream(path.join(__dirname, 'src/js/vendor', depPkg.main.split('/').pop()	)));
	    		}
	    	});
	    }
	});