v1.40.1

Changed

• Bump browserify to v16 [#2923]
• Bump glslify to v6.2.1 [#2923]
• Use color-normlize@1.3.0 throughout code base [#2923]

Fixed

• Fix logic for hiding zero lines when they conflict with axis lines [#2936]
• Fix exponentformat values 'e' and 'E' on log axes [#2921]
• Fix dynamic layer ordering of heatmap and carpet traces [#2917]
• Fix Plotly.downloadImage when using graph id or figure object
  as first argument [#2931]
• Fix regl-based rendering when WebGL buffer dimensions don't match canvas
  dimensions [#2939]