rasterio driver - authentication

I really like intake-stac and together with xpublish it becomes a very powerful solution :-)

1. Open Assets

The example shown in the notebook using Landsat data @AWS is great. The assets are freely available and thus rasterio simply accesses those resources using the href

2. Assets requiring authentication

I've got a use-case where the assets require a simple authentication mechanism. With such cases, I usually update the href for rasterio with:

```python
def get_vsi_url(enclosure, username, api_key):


parsed_url = urlparse(enclosure)

url = '/vsicurl/%s://%s:%s@%s/api%s' % (list(parsed_url)[0],
username,
api_key,
list(parsed_url)[1],
list(parsed_url)[2])

return url
```
Would such an approach be possible with intake-stac ?