The gendocs step in Travis generally leads to hard-to-interpret error output. We should consider ways to make this clearer. It's also a bit fragile, because it false-positives whenever any git file is modified, not just when a contributor forgot to generate docs.

Ideas:

• Change this step to be a bit stricter, and only check if README.md is modified
• Rewrite this as a unit test, which fails if README.md is poorly formatted
• Refactor the gendocs script into a function which returns the correct README text. Running in script mode would actually modify the README in-place.