Jest test for edit clearcompleted

[fithamlak]

`Jest test for edit clear completed Requirements are implemented

• Jest test for edit clear completed
• Create a test file(s) ([..].test.js) for a file(s) containing the following functions:
  • a function for editing the task description
  • a function for updating an item's 'completed' status.
  • the "Clear all completed" function.
• Use the mock storage object you have created in Part 1 of this project to mock the localStorage updates.
• Make sure you group your tests using the describe() method.
• Check the test coverage. `Optional, but Implemented