- Update to 1.1.0:
* added meta.readstat_variable_types to track the type of binary
variable in the original file.
* Adding better error message for not accepting certain files types in
multiprocessing, solves #105
* Fixing #106 writing failing when row 0 is removed from dataframe.
* Removing numpy deprecated objects solves #107.
* Adding support for pathlib.Path, soves #110.
* fixing order of categories
* Added formats_as_ordered_category to get an ordered category.
* Added value_formats in order to be able to set the variable format when
writing.
- Do not build on Python 3.6, due to no NumPy.