- Updated Plotly.js to version 1.49.1. See the

[plotly.js CHANGELOG](https://github.com/plotly/plotly.js/blob/master/CHANGELOG.md#1491----2019-07-31)

for more information.

- Bars in the figures produced by the `create_gantt` figure factory may now be hidden by clicking on the legend ([#1665](https://github.com/plotly/plotly.py/pull/1665)). Special thanks to [@csabaszan](https://github.com/csabaszan) for this contribution!

- Improved performance when serializing figures containing large numpy arrays ([#1690](https://github.com/plotly/plotly.py/pull/1690)). Special thanks to [@miriad](https://github.com/miriad) for this contribution!

- Added new renderers for displaying figures from within the Databricks and CoCalc notebook services ([#1703](https://github.com/plotly/plotly.py/pull/1703))

- Added `indicator` traces ([plotly/plotly.js#3978](https://github.com/plotly/plotly.js/pull/3978))

- Added `choroplethmapbox` traces ([plotly/plotly.js#3988](https://github.com/plotly/plotly.js/pull/3988))

- Added `densitymapbox` traces ([plotly/plotly.js#3993](https://github.com/plotly/plotly.js/pull/3993))

- Added new mapbox `style` values: `open-street-map`, `carto-positron`, `carto-darkmatter`,

`stamen-terrain`, `stamen-toner`, `stamen-watercolor` and `white-bg`

that do not require a Mapbox access token ([plotly/plotly.js#3987](https://github.com/plotly/plotly.js/pull/3987), [plotly/plotly.js#4068](https://github.com/plotly/plotly.js/pull/4068))

- Added support for `sourcetype` value `raster` and `image` and `type` `raster`

for mapbox layout layers ([plotly/plotly.js#4006](https://github.com/plotly/plotly.js/pull/4006))

- Added `below` attribute to `scattermapbox` traces ([plotly/plotly.js#4058](https://github.com/plotly/plotly.js/pull/4058))

- Added support for `below: 'traces'` in mapbox layout layers ([plotly/plotly.js#4058](https://github.com/plotly/plotly.js/pull/4058))

- Added `sourceattribution` attribute to mapbox layout layers ([plotly/plotly.js#4069](https://github.com/plotly/plotly.js/pull/4069))

- Added `labelangle` and `labelside` attributes to `parcoords` traces ([plotly/plotly.js#3966](https://github.com/plotly/plotly.js/pull/3966))

- Added `doubleClickDelay` config option ([plotly/plotly.js#3991](https://github.com/plotly/plotly.js/pull/3991))

- Added `showEditInChartStudio` config option ([plotly/plotly.js#4061](https://github.com/plotly/plotly.js/pull/4061))

- Fixed "The truth value of an array with more than one element is ambiguous" error when specifying subplot titles as numpy array of strings ([#1685](https://github.com/plotly/plotly.py/pull/1685)). Special thanks to [@MrQubo](https://github.com/MrQubo) for this contribution!

- The `line_3d` plotly express function was not visible by default when importing `*` from `plotly.express` ([#1667](https://github.com/plotly/plotly.py/pull/1667/files))