Scraper issue with rickbayless

Recipe URL with the issue: - [https://www.rickbayless.com/recipe/mango-guacamole/](https://www.rickbayless.com/recipe/mango-guacamole/) Which data is not being scraped correctly? (e.g. ingredients, instructions, etc): `yields` : the example site uses a custom yield implementation which returns the string `2 1/2 cups`. When running this through `get_yields` it returns `2 cups`. Losing the `1/2` cup. Input: `2 1/2 cups` Output `2 cups` Expected Result: `2.5 cups` or `2 1/2 cups` Discovered during review of #1889