Release v4.9.0

What's Changed

• Migrate to pyproject.toml and modernize a little bit the CI by David Caro (@Terseus) in #540
• Migrate the test suite to vcrpy by David Caro (@Terseus) in #541
• Add Contributing guidelines by David Caro (@Terseus) in #544
• got rid of problematic function by rheophile10 in #542
• Replace nested_to_record with json_normalize by David Caro (@Terseus) in #548
• Prevent 301 by David Caro (@Terseus) in #547
• Adds Multirange Interest Over Time by Magico (@magico) in #552
• Fix 429 errors (Fixes #354, #413, #492, #523, #535, #538) and fix pandas frame.append deprecation warning (Fixes #525) by Joshua Lochner (@xenova) in #553

New Contributors

• David Caro (@Terseus) made their first contribution in #540
• rheophile10 made their first contribution in #542
• Magico (@magico) made their first contribution in #552
• Joshua Lochner (@xenova) made their first contribution in #553

Full Changelog: v4.8.0...v4.9.0