How to use the fancy-log.bind function in fancy-log

args.browsers = (args.browser || 'chrome').split(',');
args.sauce = args.sauce ? true : false;

var BROWSERS = ['chrome', 'firefox'];
if (args.sauce) { BROWSERS.push('explorer'); }

var MOBILE_BROWSERS = ['android', 'ios', 'iphone', 'ipad', 'android_phone'];

process.env.SAUCE_CONNECT_VERSION = process.env.SAUCE_CONNECT_VERSION || '4.5.1';
process.env.SAUCE_CONNECT_VERBOSE = false;

var PROXY_PORT = 5050;
var expressPort = 3000; // incremented after each test to avoid collision

var debugLog = log.bind(log);
var warnLog = log.warn.bind(log);
var errorLog = log.error.bind(log);

function buildMochaOpts(opts) {
  var mochaOpts = {
    flags: {
      u: 'bdd-with-opts',
      R: 'spec',
      c: true,
    },
    exit: true,
    bin: path.join(__dirname,  'node_modules/.bin/' + ((process.platform !== "win32") ? 'mocha' : 'mocha.cmd')),
    concurrency: args.concurrency | process.env.CONCURRENCY || 3
  };
  if(args.grep) {
    mochaOpts.flags.g = args.grep;

function rebundle(file) {
    if (file) {
        log('Rebundling,', path.basename(file[0]), 'has changes.');
    }

    return this.bundle()
        .on('error', log.bind(log, 'Browserify Error'))         // log errors if they happen
        .pipe(source(outfile))
        .pipe(buffer())
        .pipe(gulp.dest(outdir)) //generate the non-minified
        .pipe(rename({extname:'.min.js'}))
        .pipe(sourcemaps.init({loadMaps:true, debug:true}))             // init source map
        .pipe(uglify())
        .pipe(sourcemaps.write('./'))
        .pipe(gulp.dest(outdir));
}

gulp.task('vendorScripts', function () {
  // Ensure package is updated.
  readPackage()
  var vb = browserify({
    debug: true,
    require: pkg.dependencies ? Object.keys(pkg.dependencies) : []
  })
  return vb.bundle()
    .on('error', log.bind(log, 'Browserify Error'))
    .pipe(source('vendor.js'))
    .pipe(buffer())
    .pipe($.sourcemaps.init({ loadMaps: true }))
    .pipe($.sourcemaps.write('./'))
    .pipe(gulp.dest('.tmp/assets/scripts/'))
    .pipe(bs.stream())
})

function (cb) {
            var self = this;
            var logger = fancyLog.bind(PLUGIN_NAME);
            try {
                deploy(opt, files, logger, function (err) {
                    if (err) {
                        self.emit('error', new pluginError(PLUGIN_NAME, err));
                    } else {
                        self.emit('end');
                    }
                    cb();
                })
            } catch (err) {
                self.emit('error', new pluginError(PLUGIN_NAME, err));
                cb();
            }
        });
};