v0.9.0 - don't require openai, tiktoken

Breaking changes

• pip install cappr will no longer install openai, tiktoken. Install them yourself, or install them using pip install "cappr[openai]". For previous versions of cappr, if you needed to install cappr without these dependencies, you had to run:

python -m pip install \
    "numpy>=1.21.0" \
    "tqdm>=4.27.0" && \
python -m pip install --no-deps cappr

• cappr.openai.api.Model no longer includes the deprecated text-* models

New features

None

Bug fixes

None