Kartothek v3.19.1

Version 3.19.1 (2021-02-24)

• Allow pyarrow==3 as a dependency.
• Fix a bug in
  ~kartothek.io_components.utils.align_categories{.interpreted-text
  role="func"} for dataframes with missings and of non-categorical
  dtype.
• Fix an issue with the cube index validation introduced in v3.19.0
  (#413).