refactor tsstats.tests.test_template.test_onlinetime
refactor tsstats.tests.test_template.test_onlinetime

* check client-count in template
* take clients as base instead for comparisons
* dynamically check all included client-objects
TODO
====
* move nick_data-dict-generation into function or fixture
* split tsstats.client.Clients into id and uuid-clients to easily compare client- and template-data

Thor77/TeamspeakStats,Thor77/TeamspeakStats