Secret key

[Tanishq-Tiwari-28]

Keep the secret key secret because it can be responsible for vulnerable attacks if exposed.
Below are steps to follow:

1. install a package called "environ" to read the content of .env files.
   .env files contain sensitive info and should be kept secret and should not be pushed into git rep.
2. change settings.py to achieve the functionality of keeping the secret key secret.