Update click version to reduce potential for dependency conflict

[mchonofsky]

Proposed change

The stringent dependency on click (>=6.1, <=7.0 I think) causes conflicts with other packages. I have

• checked the click change log to check that the functionality in pyicloud is not affected by this change;
• run the tests with click 8.0.3, which pass;
• updated requirements.txt to change the required version of click.

(Fixes #289)

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New service (thank you!)
• New feature (which adds functionality to an existing service)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests
• Documentation or code sample

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works. There is no new code

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated to README not applicable

[nesyuk]

Hi! Is there a chance that this PR is going to be merged soon? I'm having a dependency problem as well.