add js to enable popover and hover message
diff --git a/R/spec_tools.R b/R/spec_tools.R
index b1892b2..76fb7dd 100644
--- a/R/spec_tools.R
+++ b/R/spec_tools.R
@@ -95,7 +95,8 @@
 #'
 #' @export
 spec_tooltip <- function(title, position = "right") {
-  position <- match.arg(position, c("right", "bottom", "top", "left", "auto"))
+  position <- match.arg(position, c("right", "bottom", "top", "left", "auto"),
+                        several.ok = TRUE)
   tooltip_options <- paste(
     'data-toggle="tooltip"',
     paste0('data-placement="', position, '"'),