Update /guides/auth-torii-with-github.md (#2208)
Update /guides/auth-torii-with-github.md (#2208)

* Update /guides/auth-torii-with-github.md

Includes minor corrections for closing bracket mismatch and preferred ember style of using fetch. Also, means no dependency on ember-ajax for this particular section atleast.

* Update guides/auth-torii-with-github.md

Removed redundant comment.

Co-authored-by: Marco Otte-Witte <7f8a65a1b0d644a6a0743ca356a89664e14e0afb@simplabs.com>

* Corrected the token provider uri

Co-authored-by: Marco Otte-Witte <7f8a65a1b0d644a6a0743ca356a89664e14e0afb@simplabs.com>
simplabs/ember-simple-auth,simplabs/ember-simple-auth