Pyobsplot

- `jsdom` renderer now uses a local http server instead of calling a script at each invocation, greatly improving rendering speed.
- Autocompletion of Plot methods should now be working in IDEs.
- Ensure that the needed version of the npm package is run if jsdom renderer is used.
- Debug mode also works with `jsdom` renderer.
- Plot generator objects now have correct `__repr__` methods.
- Update anywidget to 0.2.3.
- Fix: "Exception not rethrown" errors in pytest.

- Add ability to specify some default spec values to plot generator objects.
- `range` objects are correctly serialized as lists for `jsdom` renderer.
- Fix: don't add styles to svg or html output if these styles are already present.
- Fix: jsdom renderer not working on Windows.

- It is now possible to use `Plot.plot()` directly when creating a plot with default settings.Thanks to [fil](https://github.com/fil) for the idea.
- GeoJson data passed as `string` instead of `dict` is serialized correctly.
- Add debug mode to output.

- Breaking change: new API, plots are now generated with a _plot generator object_ created by calling `Obsplot()`. Thanks to [fil](https://github.com/fil) for the idea.
- Fix: wrong `__version__` value.

- Fix: plot not recreated correctly on widget value change.
- Fix: add watchfiles to dependencies to prevent error in Colab.

- Fix: mixing renderers in Jupyter lab moves all outputs to widgets.
- Compatibility with Python 3.8.