Add full test coverage to project #5
Description
Currently, only AsyncClient has test coverage, which is not automated.
While the tests for AsyncClient test its core functionality, it is only part of the project, with the synchronous Client having no tests whatsoever. This means that any updates to Client will rely on functional tests from the both the contributer(s) and maintainers, which is both time consuming and likely to miss details.
To fix this, I would like to add unittests for Client to ensure it has at least the same test coverage as AsyncClient. Additionally, I would like to add automated testing to the project's workflows, which will save the time of maintainers when reviewing PR's.