Added taxonomies support

[justinpolygon]

Added taxonomies support to vx client since it appeared in the rest spec.

$ python3 examples/rest/stocks-taxonomy.py
[
    Taxonomy(
        category="revenue_streams",
        reason="The text mentions revenue earned from the sale of digital goods or products, such as software licenses, e-books, music downloads, or digital media content.",
        relevance=None,
        tag="digital_product_sales",
        ticker="AAPL",
    ),
    Taxonomy(
        category="revenue_streams",
        reason="The text mentions revenue generated from the licensing of intellectual property rights to third parties, including franchise rights, patent licensing, brand licensing, and the receipt of royalties for authorized use of intellectual property like music royalties, book royalties, or patent royalties.",
        relevance=None,
        tag="licensing_and_royalties",
        ticker="AAPL",
    ),
]

[justinpolygon]

Closing for now.