Fix CI build

Change-Id: I94958f7b7409732b6ab172908996eacb04d25c8f
diff --git a/R/utils.R b/R/utils.R
index dba1921..ddd11a1 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -1,7 +1,7 @@
 # Most here is from thesisdown for the posterdown_pdf option
 find_file <- function(template, file) {
   template <- system.file("rmarkdown", "templates", template, file,
-                          package = "posterdown")
+                          package = "posterdown.ids")
   if (template == "") {
     stop("Couldn't find template file ", template, "/", file, call. = FALSE)
   }