Decrease ggplot2 base_size from 14 to 12

Change-Id: I94de6fd74922d131a92c51ff3bd02bea79a7ab56
diff --git a/R/ggplot-theme.R b/R/ggplot-theme.R
index a5f297c..39ab83e 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 = 14,
+theme_ids <- function(base_size = 12,
                      base_family = idsBaseFontFamily,
                      style = c("default", "light", "dark"),
                      bgcolor = NULL) {