Refactored Currency Script project folder structure

[sue-lim]

Refactored Currency Script project folder into modular structure

[FEATURE] Currency Script | Refactor monolithic script into modules #429

Summary

Refactored Currency Script project folder into modular structure including source / tests directories

Description

The changes are as follows:

• New Source Folder
  -- Relocated currency.py and renamed to currencies.py
  -- Relocated currency_calculator and renames to converter.py
  -- Added api_handler.py
• New Test Folder
  -- Added test_api_handler.py
  -- Added test_currencies.py
  -- Added test_converter.py
• Added README
• Added setup.py
• Added requirements.txt

Checks

in the repository

• Made no changes that degrades the functioning of the repository
• Gave each commit a better title (unlike updated README.md)

in the PR

• Followed the format of the pull_request_template
• Made the Pull Request in a small level (for the creator's wellfare)
• Tested the changes you made

Thank You,
Sue

[sue-lim]

@DhanushNehru - please kindly approve PR.