Dash

Dash and Dash Renderer
Added
- [1508](https://github.com/plotly/dash/pull/1508) Fix [#1403](https://github.com/plotly/dash/issues/1403): Adds an x button
to close the error messages box.
- [1525](https://github.com/plotly/dash/pull/1525) Adds support for callbacks which have overlapping inputs and outputs. Combined with `dash.callback_context` this addresses many use cases which require circular callbacks.

Changed
- [1503](https://github.com/plotly/dash/pull/1506) Fix [#1466](https://github.com/plotly/dash/issues/1466): loosen `dash[testing]` requirements for easier integration in external projects. This PR also bumps many `dash[dev]` requirements.

Fixed
- [1530](https://github.com/plotly/dash/pull/1530) Dedent error messages more carefully.
- [1527](https://github.com/plotly/dash/issues/1527) 🐛 `get_asset_url` now pulls from an external source if `assets_external_path` is set.
- updated `_add_assets_resource` to build asset urls the same way as `get_asset_url`.
- updated doc string for `assets_external_path` Dash argument to be more clear that it will always be joined with the `assets_url_path` argument when determining the url to an external asset.
- [1493](https://github.com/plotly/dash/pull/1493) Fix [#1143](https://github.com/plotly/dash/issues/1143), a bug where having a file with one of several common names (test.py, code.py, org.py, etc) that imports a dash component package would make `import dash` fail with a cryptic error message asking whether you have a file named "dash.py"

Dash Core Components
Fixed
- [905](https://github.com/plotly/dash-core-components/pull/905) Make sure the `figure` prop of `dcc.Graph` receives updates from user interactions in the graph, by using the same `layout` object as provided in the prop rather than cloning it. Fixes [#879](https://github.com/plotly/dash-core-components/issues/879).
- [903](https://github.com/plotly/dash-core-components/pull/903) Part of fixing dash import bug https://github.com/plotly/dash/issues/1143

Updated
- [911](https://github.com/plotly/dash-core-components/pull/911), [#906](https://github.com/plotly/dash-core-components/pull/906)

Changed
- [1442](https://github.com/plotly/dash/pull/1442) Update from React 16.13.0 to 16.14.0
Fixed
- [1434](https://github.com/plotly/dash/pull/1434) Fix [#1432](https://github.com/plotly/dash/issues/1432) for Julia to import non-core component packages without possible errors.

Changed
- [1448](https://github.com/plotly/dash/pull/1448) Provide a hint in the callback error when the user forgot to make `app.callback(...)` a decorator.

Fixed
- [1426](https://github.com/plotly/dash/pull/1426) Fix a regression caused by `flask-compress==1.6.0` causing performance degradation on server requests

Fixed
- [1415](https://github.com/plotly/dash/pull/1415) Fix a regression with some layouts callbacks involving dcc.Tabs, not yet loaded dash_table.DataTable and dcc.Graph to not be called
- [1416](https://github.com/plotly/dash/pull/1416) Make callback graph more robust for complex apps and some specific props (`width` in particular) that previously caused errors.