ENDPOINT: POST /add_message.

ENDPOINT: GET /.

ENDPOINT: POST /login.

ENDPOINT: GET /login.

ENDPOINT: GET /logout.

ENDPOINT: GET /ping.

ENDPOINT: GET /register.

ENDPOINT: POST /register.

ENDPOINT: GET /sim/fllws/:username.

ENDPOINT: GET /sim/msgs/:username.

ENDPOINT: GET /sim/latest.

ENDPOINT: GET /sim/msgs.

ENDPOINT: POST /sim/fllws/:username.

ENDPOINT: POST /sim/msgs/:username.

ENDPOINT: POST /sim/register.

ENDPOINT: GET /public.

ENDPOINT: GET /:username/follow.

ENDPOINT: GET /:username/unfollow.

ENDPOINT: GET /:username.

Registration Helper Function.