decrease ggplot2 base_size from 12 to 10

Change-Id: I63eae80887c7cea54a0ae0c568427b371f31e26a
diff --git a/R/ggplot-theme.R b/R/ggplot-theme.R
index a30e7d0..7db58bd 100644
--- a/R/ggplot-theme.R
+++ b/R/ggplot-theme.R
@@ -24,7 +24,7 @@
 #' @family themes ids
 #' @importFrom ggplot2 theme element_rect element_text element_line element_blank
 #' @export
-theme_ids <- function(base_size = 12,
+theme_ids <- function(base_size = 10,
                      base_family = idsBaseFontFamily,
                      style = c("default", "light", "dark"),
                      bgcolor = NULL) {