Move 'with_sks_mock' out of individual specs, into 'config.before(:suite) do'
- This would reduce the overall test time, as the server is spawned only once.
- It might help with the still ongoing FTBFS errors during reproducible tests.
- I didn't test this up until now, but: Would this block all code after 'config.before(:suite) do', i.e. the actual test suite, because the function yields the server, and kills it afterwards. If it doesn't return, would this block the test suite from start?