Feature/exclude from file

Added an option `excludeFromFile`, which will look inside a file and make a regexp with what's inside that file to add it as the export option.

For example, from a file with this content::.

```
test/ignore_this.js
lib/external_lib.js
node_modules
```

It will convert it to:

```js
/test\/ignore_this\.js|lib\/external_lib\.js|node_modules/
```

And pass it as the `exclude` option.