add test and requirements file

[rkeur7]

This test will fail b/c it depends upon re-generation --> This PR will be merged with the open Speakeasy PR.
I kept it separate so it will not be over-written by new generations.

[github-actions]

Tests	Skipped	Failures	Errors	Time
13	0 💤	1 ❌	0 🔥	10.911 ⏱

Unit Failures

Test	Message
test_service_groups	assert False ; + where False = isinstance(ServiceLevelWithParent(name=None, terms=None, token=None, extended_token=None, parent_servicelevel=None), ServiceLevel)