assertthat, dplyr (>= 0.7), lubridate, magrittr, purrr, rlang,
stringr, tibble, tidyr (>= 0.7.1)
broom, covr, gapminder, knitr, testthat, tidyr
broom, covr, gapminder, knitr, testthat, tidyr (>= 1.0.0)
broom, covr, gapminder, knitr, rmarkdown, testthat, tidyr (>=
1.0.0)