Fix potential vulnerabilities due to outdated requirements

There are some outdated requirements which can open potential security threats. Hence we should update the vulnerable package versions as suggested by Github. Here is the list of upgrades to be done (as suggested by Github):
`django==1.11.18`

## Do you like to work on this issue?
Yes

Start by locating the dependency requirements file and checking GitHub's advisory for django==1.11.18 to identify the required secure version. Update the dependency while checking compatibility with the project's Python/Django code, then run the available test or security checks and confirm the vulnerability is resolved.

Written by the indexing model from the issue text.