Stop skipping tests unnecessarily

There is a bug in the logic of ClusterFixture.serverVersionGreaterThan. If you pass it a string like "5.0". it will parse it and then create the ServerVersion instance with [5, 0, 0] and compare it against the actual server version. But once the first 5.0 patch release is out, a test with {{@IgnoreIf({ serverVersionGreaterThan('5.0') }) }} will be incorrectly skipped when running against a 5.0.1 server. The intention is that the test is only skipped when running against the next minor release, e.g. 5.1.*.