Dash

Added
- [483](https://github.com/plotly/dash/pull/483) Experimental `--r-prefix` option to `dash-generate-components`, optionally generates R version of components and corresponding R package.

Added
- [490](https://github.com/plotly/dash/pull/490) Add `--ignore` option to `dash-generate-components`, defaults to `^_`.

Removed
- [renderer108](https://github.com/plotly/dash-renderer/pull/108) Unused login api and Authentication component

Fixed
- Add `key` to rendered components, fixing [renderer379](https://github.com/plotly/dash-core-components/issues/379)

Added
- [487](https://github.com/plotly/dash/pull/487) Add specific Dash exception types to replace generic exceptions (`InvalidIndexException`, `DependencyException`, `ResourceException`)

Fixed
- [485](https://github.com/plotly/dash/pull/485) Fix typo in missing events/inputs error message

Changed
- [484](https://github.com/plotly/dash/pull/484) Mute dash related missing props docstring from extract-meta warnings

Added
- [478](https://github.com/plotly/dash/pull/478), [renderer#104](https://github.com/plotly/dash-renderer/issues/104) Support for .map file extension and dynamic (on demand) loading
- [renderer107](https://github.com/plotly/dash-renderer/pull/107) [Redux devtools](https://github.com/zalmoxisus/redux-devtools-extension) support