not issue feature file already downloaded
i suggest to add a check to see if the file was already downloaded
I passed some hour to figure out that i need to close the stream else it's not working.


here the code : 

```
const processUpload = async (upload) => {
  const { stream, filename, mimetype, encoding } = await upload;
  const el = existInDB(filename);
  if (el.length > 0) {
    stream.resume();
    stream.on('end', () => {
      console.log('got to the end, but did not read anything');
    });
    var out = el.map(a => Object.assign({}, a))
    return out[0]
  } else {
    const { id, path } = await storeFS({ stream, filename });
    return storeDB({ id, filename, mimetype, encoding, path }); 
  }
}
```

```
export const existInDB = filename => { 
  return _.toArray(db.get("uploads")).filter(function(e) {
    return e.filename === filename;
  });
};

```
