Phase 3 - Change code so that temp files download into a temp folder

[rdeodha]

Currently, if a YouTube video has caption disabled, the application downloads the audio from the video into a file called temp.mp4
This file gets downloaded in the root project folder, which is not good practice. We need to make a temp folder in the root directly where all temporary files get downloaded. Additionally, after the application is done with the temporary files, it should delete them off disk.

To test, use this YouTube video: https://www.youtube.com/watch?v=2kttVyakHN4

[rdeodha]

Also gitignore should ignore all files in the temp folder.