metomi/isodatetime#3: add recurrence parser tests
update
metomi/isodatetime#3: refactor to use unittest
metomi/isodatetime#3: fix tests and code
Fix interval week representation, truncated time representation
Fix error names, decimal formatting, and recurrence edge cases
Merge pull request #8 from benfitzpatrick/3.recurrence-testing

Test suite update

Provides a more comprehensive test suite for the ISO 8601 functionality, implemented using the Python `unittest` module.