bump required version of htmlwidgets to 1.3 (for async in shiny)

Author: cpsievert

DESCRIPTION

@@ -33,7 +33,7 @@ Imports:
     viridisLite,
     base64enc,
     htmltools,
-    htmlwidgets (>= 1.2),
+    htmlwidgets (>= 1.3),
     tidyr,
     hexbin,
     RColorBrewer,

R/shiny.R

@@ -45,9 +45,6 @@ renderPlotly <- function(expr, env = parent.frame(), quoted = FALSE) {
 # Converts a plot, OR a promise of a plot, to plotly
 prepareWidget <- function(x) {
   if (promises::is.promising(x)) {
-    if (utils::packageVersion("htmlwidgets") < "1.2.1") {
-      warning("Async rendering of htmlwidgets requires v1.2.1 (or higher) of the htmlwidgets package.")
-    }
     promises::then(x, ggplotly)
   } else {
     ggplotly(x)