Peppy

Added

- Support for multiple subsample tables
- License file to the package source distribution

Changed

- Package authors list

**This version introduced backwards-incompatible changes.**

Added

- attribute duplication functionality
- config importing functionality
- attribute removal functionality
- possibility to define multi-attribute rules in attribute implication

Changed

- Project configuration file to follow [PEP2.0.0](http://pep.databio.org/en/2.0.0/specification/) specification. Browse the specification for changes related to config format
- Do not require `sample_name` attribute in the sample table

Changed

- Remove `is_command_callable` from `utils` module; instead, refer to [`ubiquerg`](https://pypi.org/project/ubiquerg/).
- It's now exceptional (rather than just a warning) for a sample table file to be missing a valid name column.

Fixed

- Empty columns in subsample tables are treated just as empty columns in sample tables (respective attributes are not included rather than populated with `nan`)

Changed

- Remove `ngstk` requirement.

Changed

- Prohibit storing reference to full `Project` object on a `Sample`.