Zero-Trust DevHub Backend Server Login

[kj4ezj]

In devrel issue 80, I stood up a backend server for the learn.eosnetwork.com DevHub portal in the DevHub AWS Account. This ticket is to implement a modern, zero-trust login mechanism for that server similar to ScaleFT. Zero-trust models are more secure, easier to use, and easier to administrate. This will almost certainly mean using AWS tooling, in which case this ticket is blocked by engineering issue 12 to setup AWS account federation for users.