Add tests for matchmaking

[bayta-darell-1400]

Type of pull request:

• Bug fix
• Feature
• Other

Description:

• Fixed minor typos in docstrings.
• Replaced variable name days for num_days to avoid shadowing name from outer scope.
• Added tests for module lib/matchmaking.py. Coverage has increased from 31% to 36%.

Related Issues:

ref #920

Checklist:

• I have read and followed the contribution guidelines.
• I have added necessary documentation (if applicable).
• The changes pass all existing tests.

Screenshots/logs (if applicable):

none