Remove reppy, add Crawl-delay, prep for 0.4.0

[micahcochran]

• Remove reppy dependency, this is a C++ dependency, replaced with Python standard library urllib.robotparser. Merging closes Issue Installation problems with reppy #10.
• Add support for Crawl-delay in robots.txt, which requires a certain number of second delay between page requests.
• Add website Foodista as a source.
• Update recipe-scrapers to work with 14.48.0. The library's interface has been improved.
• Correct some of the typing syntax. There are still some issues.
• Add requirements-dev.txt for development. It adds external libraries typing.
• Prepare for version 0.4.0.

TODO: Update requirements.txt based on soon scrape-schema-recipe release.
Update requirements.txt to newer dependencies in f07ecef