Refactor ZIP archiving methods for thread safety

[mrsaicharan1]

Is your feature request related to a problem? Please describe.
Currently, make_archive from shutil is not thread-safe & this makes it difficult in the scenarios of multiple users requesting the same file at a particular instant.

Describe the solution you'd like

https://bugs.python.org/issue14099
https://docs.python.org/3.5/whatsnew/changelog.html#id93
From Python 3.5.5, writing to zipfile has been made thread-safe and this should be followed for archiving throughout the codebase to ensure proper archive downloads.

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