; --> &&
use knitr:::html_vignette
the code can be read from formatR::usage()
roxygenize() might create new Rd files, so we should list.files() after roxygenize()
use the svg badge
simplify travis script, and deploy to XRAN after success
add rmarkdown to Suggests, and install pandoc for the vignette
deploy the package to xran, and the vignette to gh-pages branch
bump version