Add convenience function geom_freq_by_year_ci

Change-Id: Id4f9c5ead478cb2dcb7d7a48580b501bd5e0c752
diff --git a/NAMESPACE b/NAMESPACE
index bb3fd5f..0e11e6f 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -44,6 +44,12 @@
 importFrom(dplyr,select)
 importFrom(dplyr,starts_with)
 importFrom(dplyr,summarise)
+importFrom(ggplot2,element_text)
+importFrom(ggplot2,geom_line)
+importFrom(ggplot2,geom_point)
+importFrom(ggplot2,geom_ribbon)
+importFrom(ggplot2,scale_x_continuous)
+importFrom(ggplot2,theme)
 importFrom(jsonlite,fromJSON)
 importFrom(lubridate,year)
 importFrom(magrittr,"%>%")