suggest jsonlite

DESCRIPTION

 Imports: 
     dplyr,
     htmltools,
-    jsonlite,
     knitr,
     miniUI,
     purrr,
     tidyr,
     utils
 Suggests: 
+    jsonlite,
     rematch2,
     stringr,
     testthat

R/gadget.R

 #'
 #' @keywords internal
 get_regex_library <- function() {
-  if (!requireNamespace("jsonlite")) {
+  if (!requireNamespace("jsonlite", quietly = TRUE)) {
     warning("Please install the `jsonlite` package to use template features")
     return(NULL)
   }