Update plotly

[pfitzseb]

and fix auto-resizing for Plotly and VegaLite.

Fixes #1716.

[pfitzseb]

With this you can get automatically resized plots with

plot(xTest, yTest, fEval, st=:surface, size=(0,0))

or

@vlplot(
    :point,
    x=:Horsepower,
    y=:Miles_per_Gallon,
    color=:Origin
)

whereas

plot(xTest, yTest, fEval, st=:surface)

or

@vlplot(
    :point,
    x=:Horsepower,
    y=:Miles_per_Gallon,
    color=:Origin,
    width=400,
    height=400
)

will show a statically sized plot.