bugs in restyle and restyle!

Hi,
I think I encountered two different bugs. I'm a new user of plotly*, so sorry if I'm just doing everything wrong.
The first is in `restyle`
```julia
julia> pl = plot(scatter(x=1:10, y=1:10))

julia> restyle(pl, 1, y=1:2:20)
ERROR: MethodError: no method matching PlotlyJS.ElectronDisplay()
Closest candidates are:
PlotlyJS.ElectronDisplay(::Base.Random.UUID) at /home/carlo/.julia/v0.6/PlotlyJS/src/displays/electron.jl:12
PlotlyJS.ElectronDisplay(::Base.Random.UUID, ::Nullable{Any}) at /home/carlo/.julia/v0.6/PlotlyJS/src/displays/electron.jl:6
PlotlyJS.ElectronDisplay(::PlotlyBase.Plot) at /home/carlo/.julia/v0.6/PlotlyJS/src/displays/electron.jl:13
```
The second in `restyle!`
```julia
julia> pl = plot(scatter(x=1:10, y=1:10))

julia> pl.plot.data[1].fields
Dict{Symbol,Any} with 3 entries:
:y => 1:10
:type => "scatter"
:x => 1:10

julia> restyle!(pl, 1, y=1:2:20)

# after this the plot is a little screwed up
julia> restyle!(pl,1,y=1:2:20)
Blink.Page(3, WebSockets.WebSocket(19, TCPSocket(RawFD(23) active, 0 bytes waiting), CONNECTED::WebSockets.ReadyState = 1), Dict{String,Any}(Pair{String,Any}("callback", Blink.#3)), Future(1, 1, 9, Nullable{Any}(true)))

julia> pl.plot.data[1].fields
Dict{Symbol,Any} with 3 entries:
:y => 1 # ?????
:type => "scatter"
:x => 1:10

```