Pass anonymous args to hc_theme_ids_dark

Change-Id: I3789849ecdf92bec150cb2d3b129fdb36f67cce9
diff --git a/R/highcharter-themes.R b/R/highcharter-themes.R
index 300e7fb..6038f84 100644
--- a/R/highcharter-themes.R
+++ b/R/highcharter-themes.R
@@ -236,7 +236,8 @@
     tooltipBackgroundColor = "#ffffffe0",
     boxplotFillColor = "#505053",
     candlestickColor = "black",
-    errorbarColor = "black"
+    errorbarColor = "black",
+    ...
   )
 }
 
@@ -267,6 +268,7 @@
     tooltipBackgroundColor = "white",
     boxplotFillColor = "#505053",
     candlestickColor = "grey",
-    errorbarColor = "grey"
+    errorbarColor = "grey",
+    ...
   )
 }