Tests/test update config

Description

After fixing some bugs at https://git.xfel.eu/gitlab/detectors/pycalibration/merge_requests/470. I have tried to refactor and introduce some tests for update_config.py

update_config.py is split in three different functions instead of one big main function:

1- main 2- test_add_negative_bools_conf 3- test_create_new_config_from_args_input

This is to reduce code complexity and to test the different parts of the SW independently.

How Has This Been Tested?

using pytest.

Relevant Documents (optional)

Types of changes

• Test (additional or refactored tests)
• Refactor (refactoring code with no functionality changes)

Checklist:

• My code follows the code style of this project.
• I have updated the documentation accordingly.
• I added tests where appropriate.

Reviewers

@kluyvert @roscar