Fix missing roxygen tag to test a clean docs build.

R/hello.R

@@ -5,7 +5,7 @@
 #' @param name Your name (character string; e.g. "john doe").
 #'
 #' @return A character string, capitalized to title case.
-#' @exportthistagdoesnotexist
+#' @export
 #'
 #' @examples
 #' hello("james bond")