Additional R build dependencies, possible missing file

[rybern]

Working on building the book. So far I've needed these R packages in addition to the ones in the README:

• ggplot2
• gridExtra
• rstan
• formatR

Now I'm getting this error:
! LaTeX Error: File 'tufte-book.cls' not found.
Maybe an uncommitted file?

[bob-carpenter]

Thanks. Depending on rstan was just a cut-and-paste error from the last bookdown I was using. I removed the library call and also a few others that weren't used and updated the real dependencies. Let me know if it builds after installing the tufte package and I'll close this issue.