caseyclements has created PR #1440: [PYTHON-3036] Improve error message for unknown MongoClient options in mongo-python-driver

Issue Text:
https://jira.mongodb.org/browse/PYTHON-3036

When an unknown kwarg was passed to MongoClient, the ConfigurationError wasn't helpful. I use the standard lib package `difflib` to look for similar known options. It appears to work pretty well.

First contribution to this mongodb. This PR / ticket doubles as SDLC tutorial. I've got a feature branch with a couple tests that I'll now use.

It will now look something like this:

```
ConfigurationError('Unknown option: auth. Did you mean: authsource, authmechanism, authoidcallowedhosts?')
```