Add PhantAuth as a supported OpenID Connect identity provider

PhantAuth was designed to simplify testing of applications using OpenID Connect authentication by making use of randomly generated users.

By using PhantAuth, you can test applications built on Okta with an unlimited number of test users.
It could bring the developers of applications using Okta considerable added value.
For most identity providers, user pre-registration is required, which makes testing rather cumbersome, especially in the case of load tests.

To learn more, please visit: https://www.phantauth.net
Test Okta login: https://www.phantauth.net/test/okta