Explicitely use and import dplyr::n

Fixes issues with dplyr 1.0

Change-Id: I73c59b00ee8fcc525084767d7520d6dfc4afb311
diff --git a/R/KorAPQuery.R b/R/KorAPQuery.R
index 596cd90..64ee8c6 100644
--- a/R/KorAPQuery.R
+++ b/R/KorAPQuery.R
@@ -113,7 +113,7 @@
 #'   mutate(year = lubridate::year(pubDate)) %>%
 #'   dplyr::select(year) %>%
 #'   group_by(year) %>%
-#'   summarise(Count = n()) %>%
+#'   summarise(Count = dplyr::n()) %>%
 #'   mutate(Freq = mapply(function(f, y)
 #'     f / corpusStats(kco, paste("pubDate in", y))@tokens, Count, year)) %>%
 #'   dplyr::select(-Count) %>%
@@ -231,7 +231,7 @@
 #' @aliases fetchNext
 #' @rdname KorAPQuery-class
 #' @importFrom purrr map_dfr
-#' @importFrom dplyr rowwise bind_rows select
+#' @importFrom dplyr rowwise bind_rows select summarise n
 #' @export
 setMethod("fetchNext", "KorAPQuery", function(kqo, offset = kqo@nextStartIndex, maxFetch = maxResultsPerPage, verbose = kqo@korapConnection@verbose) {
   if (kqo@totalResults == 0 || offset >= kqo@totalResults) {
diff --git a/R/reexports.R b/R/reexports.R
index 1a4d729..1630dd9 100644
--- a/R/reexports.R
+++ b/R/reexports.R
@@ -25,6 +25,9 @@
 #' @importFrom dplyr summarise
 #' @export
 dplyr::summarise
+#' @importFrom dplyr n
+#' @export
+dplyr::n
 #' @importFrom tidyr complete
 #' @export
 tidyr::complete