Cartesian plot with 'hoverinfo': 'text' or 'y+text' and 'hovermode': 'x' does not show hover text

[etpinard]

e.g.

Plotly.plot(Tabs.fresh(), [
    {
        x: [1, 2, 3],
        y: [10, 30, 15],
        text: ['one', 'two', 'three'],
        name: 'first trace',
        hoverinfo: 'text'
    }],
    {
        hovermode: 'x'
    }
);

[cldougl]

Done in #70