Sign up endpoint notes

[amulya]

-Do not return render_template() from endpoint; return JSON object (important: include status code. 200, 404, 400, etc)
-request.form may not work to access form info. We may have to access info using request.data or something else. Must test this.
-set up database interaction (wait on amulya to set up database first)
-add error checking once you obtain/check info against database

[amulya]

T0 do still:
-add error checking