Preview version of Atlas 3 website now available

[chrisknoll]

We have a preview version of Atlas 3 available at:
https://atlas-preview.ohdsi.org/atlas/

For demo user, you can log in as ohdsi/ohdsi.

Please feel free to navigate through the new UI, and please share feedback on flow and User Experience (UX) concerns. At this point, there are many known bugs and incomplete implementation for some of the features, and so we want to hear about those issues you might have, but we fully expect lots of issues. Feel free to open an issue on this repo for anything you feel is a bug.