options.modules default value

The README says that `options.modules` default value is an empty array. However, If using this task without the `modules` option I get:

<pre>
Users/jviotti/Projects/Temporal/sweet/node_modules/gulp-sweetjs/node_modules/each-async/each-async.js:31
		var l = arr.length;
		           ^
TypeError: Cannot read property 'length' of undefined
    at each (/Users/jviotti/Projects/Temporal/sweet/node_modules/gulp-sweetjs/node_modules/each-async/each-async.js:31:14)
    at Stream.<anonymous> (/Users/jviotti/Projects/Temporal/sweet/node_modules/gulp-sweetjs/index.js:59:4)
    at Stream.stream.write (/Users/jviotti/Projects/Temporal/sweet/node_modules/through/index.js:26:11)
    at Stream.ondata (stream.js:51:26)
    at Stream.EventEmitter.emit (events.js:95:17)
    at queueData (/Users/jviotti/Projects/Temporal/sweet/node_modules/gulp/node_modules/map-stream/index.js:38:21)
    at next (/Users/jviotti/Projects/Temporal/sweet/node_modules/gulp/node_modules/map-stream/index.js:68:5)
    at /Users/jviotti/Projects/Temporal/sweet/node_modules/gulp/node_modules/map-stream/index.js:77:7
    at /Users/jviotti/Projects/Temporal/sweet/node_modules/gulp/lib/createInputStream/bufferFile.js:7:5
    at fs.js:266:14
</pre>

I enforced the default value you're proposing with a logical expression, which will evalute the first parameter of `eachAsync` to an empty array if `options.modules` doesn't exists.

Cheers.