plotting svg

Wondering if such a snippet would come in handy to others? This plots the Plotly plots in SVG. Comes in handy when I export my notebooks to share with others using html.

```julia
function plot_svg(p::PlotlyJS.SyncPlot)
fn,_ = mktemp()
fn = join([fn, ".svg"])
savefig(p, fn)
open(fn) do f
display("image/svg+xml", read(f, String))
end
end
```