Imageupload

* fixed white spaces (so my text editor stop complaining)
* support for uploading png,jpg,jpeg and gif to s3


add in `package.json` and in cli type `npm run-script ci`

```js
  "scripts": {
    "ci": "mkdir -p public/assets && cp -r public/images/* public/assets/ && node_modules/minimus/bin/minimus"
  }
```