Import lifecycle (#3902)

* Import lifecycle

* revert previous and avoid copying dplyr::vars

Author: romainfrancois

DESCRIPTION

@@ -254,6 +254,6 @@ Collate:
     'zxx.r'
     'zzz.r'
 VignetteBuilder: knitr
-RoxygenNote: 7.0.2
+RoxygenNote: 7.1.0
 Roxygen: list(markdown = TRUE)
 Encoding: UTF-8

R/zzz.r

@@ -50,12 +50,6 @@ pathGrob <- NULL
   ggplot_global$date_origin <- date - unclass(date)
   time <- Sys.time()
   ggplot_global$time_origin <- time - unclass(time)
-
-  # To avoid namespace clash with dplyr.
-  # It seems surprising that this hack works
-  if (requireNamespace("dplyr", quietly = TRUE)) {
-    vars <<- dplyr::vars
-  }
 }
 
 release_questions <- function() {