Deleting a Family and Tracking Returns Old Location

[cpressman]

This may all be connected with #156 but here are some more details:

I did all of this inside the latest docker container
Steps to reproduce:

1. Use POST data for a device until you have enough data to make a guess (with the same location)
2. Use GET location_basic to confirm the guess. Since I only trained 1 position the probability should be 1
3. Use DELETE database
4. Confirm using GET location that the family no longer exists
5. Use POST data like in Can I run this on a raspberry pi? #1 but with an empty location. This should mean there is still no training data but the database file should get recreated
6. Use GET location_basic like in step 2

Expected results:
No guesses found

Actual results
The location trained in step 1 is still guessed.

Possible solution:
When deleting the database the ai file should possibly get deleted as well.

[IoTThinks]

Seems to have the same issue.

[IoTThinks]

@cpressman Do you have any idea how to clear database of AI server?
Thanks a lot.