make sure colorbar points are lists of first point and update tests accordingly

Author: Kully

plotly/tests/test_optional/test_figure_factory.py

@@ -903,9 +903,9 @@ def test_trisurf_all_args(self):
                       'mode': 'markers',
                       'showlegend': False,
                       'type': 'scatter3d',
-                      'x': -1.0,
-                      'y': -1.0,
-                      'z': 1.0}],
+                      'x': [-1.0],
+                      'y': [-1.0],
+                      'z': [1.0]}],
             'layout': {'height': 800,
                        'scene': {'aspectratio': {'x': 1, 'y': 1, 'z': 1},
                                  'xaxis': {'backgroundcolor': 'rgb(230, 230, 230)',

plotly/tools.py

@@ -3352,9 +3352,9 @@ def _trisurf(x, y, z, simplices, show_colorbar, edges_color,
             colorscale = FigureFactory._convert_colorscale_to_rgb(colorscale)
 
             colorbar = graph_objs.Scatter3d(
-                x=x[0],
-                y=y[0],
-                z=z[0],
+                x=x[0:1],
+                y=y[0:1],
+                z=z[0:1],
                 mode='markers',
                 marker=dict(
                     size=0.1,