Support Babbage

[schneiderfelipe]

This seems to be the only text completion model that makes sense supporting, as it costs 25% the price of GPT-3.5 Turbo.

In particular, it makes no sense to support Curie or DaVinci, as they cost the same or more, and seem to perform more poorly than GPT-3.5 Turbo:

           model  prompt  completion  comparison  order
7  Ada Embedding  0.0004      0.0004        0.20      0
3            Ada  0.0004      0.0004        0.20      1
4        Babbage  0.0005      0.0005        0.25      2
5          Curie  0.0020      0.0020        1.00      3
6        Davinci  0.0200      0.0200       10.00      4
2  GPT-3.5 Turbo  0.0020      0.0020        1.00      5
0       GPT-4 8K  0.0300      0.0600       30.00      6
1      GPT-4 32K  0.0600      0.1200       60.00      7