* Removed `auto_start_request` from __init__ in the pymongo >= 3.0 case.
* Using only the MongoClient for pymongo >= 3.0 case, since
MongoReplicaSetClient is labelled deprecated and all functionality
has been merged to MongoClient.
* Wrappers has a overriding `__getitem__` method added. In pymongo < 3.0 the
`__getitem__` method (used when calling c[db_name]) called the `__getattr__`
method (used when calling c.db_name), so wrappers did not need to override both then.
In pymongo > 3.0 this is not the case.
* Tests in test_config.py use `mongo.cx.address` property instead of
`host` and `port` properties of the MongoClient in the pymongo >= 3.0 case,
since they have been removed. All tests using this property also
sleeps a short time since the client needs some time to establish
connection to MongoDB and set the proper values, otherwise the tests fails.
* The `safe` keyword is deprecated for insert method, though only flagged
in pymongo 2.x. Change all these to `w=1` which has equal effect.
`insert` method also has a deprecation warning in pymongo 3.0.x,
so `insert_one` is used instead in these cases.