[#72214120] Wrote request spec for API posts.

* JSON request headers must be sent with each POST.
* To do: Specify request headers if users are POSTing to the API.

Signed-off-by: Ellie Schneiders <ems2141@gmail.com>
Resolved merge conflicts, incoporated Mikes refactoring.

Signed-off-by: Ellie Schneiders <ems2141@gmail.com>