Quantile lines on violin plots are not rendered

When using draw_quantiles argument of ggplot2::geom_violin and converting the result with plotly::ggplotly, the quantile lines are shown on ggplot but not on plotly.

library(ggplot2)
library(plotly)
#> 
#> Attaching package: 'plotly'
#> The following object is masked from 'package:ggplot2':
#> 
#>     last_plot
#> The following object is masked from 'package:stats':
#> 
#>     filter
#> The following object is masked from 'package:graphics':
#> 
#>     layout

g <- ggplot(iris, aes(Species, Sepal.Length)) +
  geom_violin(draw_quantiles = c(0.25, 0.5, 0.75))
g

# ggplotly(g)

^{Created on 2018-11-12 by the reprex package (v0.2.1)}

I'm not able to provided the result of ggplotly above. Still, by executing ggplotly(g) above, you'll find that the quantile lines disappear:

使用提供的 R 示例，通过 ggplot2::geom_violin(draw_quantiles = c(0.25, 0.5, 0.75)) 和 plotly::ggplotly 重现该问题。跟踪小提琴图层及其分位数线的转换过程，然后验证转换后的图中是否像 ggplot 中一样显示分位数线。