openEO Python client v0.8.1

Added

• Support nested callbacks inside array arguments, for instance in array_modify, array_create
• Support array_concat
• add ProcessGraphUnflattener and PGNodeGraphUnflattener to unflatten a flat dict representation of a process
  graph to a PGNode graph (EP-3609)
• Add Connection.datacube_from_flat_graph and Connection.datacube_from_json to construct a DataCube
  from flat process graph representation (e.g. JSON file or JSON URL) (EP-3609)
• Add documentation about UDP unflattening and sharing (EP-3609)
• Add fit_curve and predict_curve, two methods used in change detection

Changed

• Update processes.py based on 1.1.0 release op openeo-processes project
• processes.py: include all processes from "proposals" folder of openeo-processes project
• Jupyter integration: Visual rendering for process graphs shown instead of a plain JSON representation.
• Migrate from Travis CI to GitHub Actions for documentation building and unit tests (#178, EP-3645)

Removed

• Removed unit test runs for Python 3.5 (#210)