Add failing test for sort + animate

[rreusser]

This PR adds a failing test for sort + transform that is fixed by #1737. It basically checks the value of calcdata after the transform has started but before it has finished in order to check that the result is as expected.

/cc @alexcjohnson @etpinard

[rreusser]

Was trying this instead, but the animation never resolves. I have no idea what to make of that…

Plotly.plot(gd, {
    data: [{
        x: [1, 2, 3], 
        y: [1, 2, 3], 
        mode: 'markers',
        transforms: [{type: 'sort', target: [1, 3, 2]}]
    }], 
    frames: [
        {name: 'frame1', data: [{y: [1, 2, 3]}]},
        {name: 'frame2', data: [{y: [3, 1, 2]}]}
    ]   
}).then(function () {;
    return Plotly.animate(gd, ['frame2'], {frame: {duration: 200, redraw: false}});
}).then(function () {
    expect(gd.calcdata[0][0].y).toEqual(3);
}).catch(fail).then(done);

[alexcjohnson]

meh, the simplified one worked for me, merged that into #1737 and closing this PR