Add unit test for AI VPN CLI: aivpn.py

[Adity20]

Is your feature request related to a problem? Please describe.
Currently, the AI VPN CLI script lacks unit tests covering functions that interact with a Redis database. To ensure robust testing without relying on an actual Redis connection, it would be beneficial to introduce mock objects for simulating Redis interactions.

Describe the solution you'd like
1.Introducing unit tests for functions interacting with Redis, such as manage_info, manage_expire for now.
2.Using mocking libraries like unittest.mock to create mock Redis client objects in the test environment.
3.Patching relevant functions within the tests to replace actual Redis calls with mock behavior.
4.Verifying the behavior of these functions by adding assertions to check if the expected actions are performed.

Expected Outcome
Improved test coverage for Redis interactions in the AI VPN CLI script.
Reduced dependency on an actual Redis connection during testing, leading to faster and more reliable test execution.