documenting this change

Author: dsweber2

tests/testthat/test-as_tibble-decay.R

@@ -8,6 +8,7 @@ test_that("as_tibble checks an attr to avoid decay to tibble", {
 })
 
 test_that("as_tibble ungroups if needed", {
+  # tsibble is doing some method piracy, and overwriting as_tibble.grouped_df as of 1.1.5
   skip_if(packageVersion("tsibble") > "1.1.4")
   edf <- jhu_csse_daily_subset %>% group_by(geo_value)
   # removes the grouped_df class

tests/testthat/test-methods-epi_df.R

@@ -131,6 +131,7 @@ test_that("Metadata is dropped by `as_tibble`", {
 })
 
 test_that("Grouping are dropped by `as_tibble`", {
+  # tsibble is doing some method piracy, and overwriting as_tibble.grouped_df as of 1.1.5
   skip_if(packageVersion("tsibble") > "1.1.4")
   grouped_converted <- toy_epi_df %>%
     group_by(geo_value) %>%