[2.0] Fix skipped tests

[alcaeus]

As evidenced in the master build, there are a bunch of skipped tests: https://travis-ci.org/doctrine/mongodb-odm/jobs/376653436#L1607. Some of these relate to sharding support, others (e.g. SchemaManagerTest) needs to be refactored.

[caciobanu]

Wanted to give $this->markTestSkipped('mongodb-driver: query logging does not exist'); a try but not sure how to fix it. We should delete the tests or the feature has to be implemented ?

[alcaeus]

So, these tests used to inject a custom logger into the LoggableCollection and LoggableDatabase classes to track every command that was run. We've decided to drop these classes in favour of more mature tools. I'll have to think of a way to trace these.

For now, the only solution would be rewriting the tests to not require logging (where possible).

[alcaeus]

Update, there are now 3 tests that need fixing:

• Doctrine\ODM\MongoDB\Tests\Functional\DocumentPersisterTest::testVersionIncrementOnUpdateSuccess
• Doctrine\ODM\MongoDB\Tests\Functional\DocumentPersisterTest::testNoVersionIncrementOnUpdateFailure
• Doctrine\ODM\MongoDB\Tests\Functional\ReferencePrimerTest::testPrimeReferencesInReferenceManyWithRepositoryMethodThrowsException