Fix broken link to BTS, closes hadley#1583

data-transform.qmd

@@ -39,7 +39,7 @@ However, knowing the package can help you find help and find related functions,
 
 To explore the basic dplyr verbs, we're going to use `nycflights13::flights`.
 This dataset contains all `r format(nrow(nycflights13::flights), big.mark = ",")` flights that departed from New York City in 2013.
-The data comes from the US [Bureau of Transportation Statistics](http://www.transtats.bts.gov/DatabaseInfo.asp?DB_ID=120&Link=0), and is documented in `?flights`.
+The data comes from the US [Bureau of Transportation Statistics](https://www.transtats.bts.gov/DL_SelectFields.aspx?gnoyr_VQ=FGJ&QO_fu146_anzr=b0-gvzr), and is documented in `?flights`.
 
 ```{r}
 flights