Create unit test for Create a Form API

## Description
As a developer,
I need have unit tests for each functionality,
so that I can be confident when building a new feature, that there are no regression on the platform.

API: `POST /api/form`

The idea is to come with 3 unit tests to test this API. You may have to mock some information to properly test it.

**Resources:**
* Writing tests for Django projects: [resource 1](https://www.django-rest-framework.org/api-guide/testing/) and [resource 2](https://docs.djangoproject.com/en/3.1/topics/testing/tools/)
* Postman documentation about this specific API: https://documenter.getpostman.com/view/11324046/Szzoaw1q?version=latest#fae4122b-fd56-4aeb-9771-97b05ff40a82

## Acceptance Criteria
### Update [Required]
- [ ] Create 3 unit tests for `POST /api/form` API

## Definition of Done
- [ ] All of the required items are completed.
- [x] Approval by 1 mentor.

## Estimation
4 hours