Fixes #94

Description

I have added, response for 201 Created in the following apps

1. org (for organisation and group)
2. user (at registration)
3. tasks (at task creation)

Type of Change: (Delete irrelevant options)

• Code
• Documentation

Code/Quality Assurance Only (Delete irrelevant options)

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

No new tests have been added. Previously defined tests pass successfully.

Creating test database for alias 'default'...
System check identified no issues (0 silenced).
...........................................................................................
----------------------------------------------------------------------
Ran 91 tests in 159.248s

OK
Destroying test database for alias 'default'...

Checklist:

• My PR follows the style guidelines of this project
• I have performed a self-review of my own code or materials
• I have commented my code or provided relevant documentation, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• Any dependent changes have been merged
• Update Swagger documentation and the exported file at /docs folder
• Update requirements.txt

Code/Quality Assurance

• My changes generate no new warnings
• My PR currently breaks something (fix or feature that would cause existing functionality to not work as expected)
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been published in downstream modules