add force redraw step in scene.plot,
add force redraw step in scene.plot,

- so that Plotly.plot promise is returned
  when rendering is completed

iongroup/plotly.js,etpinard/plotly.js,asolagmbh/plotly.js,aburato/plotly.js,etpinard/plotly.js,plotly/plotly.js,aburato/plotly.js,plotly/plotly.js,iongroup/plotly.js,plotly/plotly.js,asolagmbh/plotly.js,plotly/plotly.js,etpinard/plotly.js,asolagmbh/plotly.js,iongroup/plotly.js