Compile knitr/Sweave documents

[csgillespie]

I've started to upload copies of book chapters/publications to github. It occurred to me that it would rstraight forward to use r-travis to test knitr documents (without altering r-travis).

I've mocked up an example work-flow at https://github.com/csgillespie/travis-examples/tree/travis-knitr

The key ideas are:

• Create a DESCRIPTION file. This file only needs a Depends: section. The install_deps function then uses this file to install any packages that are needed by knitr/Sweave. In my example, the document just depends on knitr.
• In the .travis.yml file, turn latex on and tweak the install step.

Comments? Should I add this under the recipes section of the wiki?

@yihui any suggestions?

[yihui]

Looks good to me! Thanks!

[craigcitro]

@csgillespie yes, please -- it would be FANTASTIC to have this in the recipes section.

[csgillespie]

Added.