[New Functional Testing] Create fake timer to test toggle_start_pause function

[tai271828]

Types of changes

• New feature
• Refactoring
• Breaking change (any change that would cause existing functionality to not work as expected)

Description

Test toggle_start_pause by invoking pytest ./tests/test_timer.py

Checklist:

• Add test cases to all the changes you introduce
• Run pytest locally to ensure all linter checks pass
• Update the documentation if necessary

Steps to Test This Pull Request

pytest under project root.

Expected behavior

7 passed, 1 warning

Related Issue

#52