OHDSI ATLAS web api only allows one login per user at a time

[TonyWildish-BH]

The OHDSI module boots with a user account created for it, grep for ATLAS_USER in the terraform and scripts directories. This user seems empirically to be able to only log in in one session at a time. If I open two VMs and log in in one of them, then in the other, the first is thrown out.

Since there's only one user in the local security DB, that means only one person in the workspace can use ATLAS at a time.

The desired result is that the ATLAS UI can be logged into from as many VMs as there are booted in the workspace, which could be many per user.

So the acceptance criteria are, if possible:

• A single user account can log in via multiple VMs at the same time
• There are user accounts for every user in the workspace, so they don't have to share the admin account.