Added - Summary operators: now it is possible to use user-defined summary operators, the following static methods were added to the ``SS3`` class: `summary_op_ngrams`, `summary_op_sentences`, and `summary_op_paragraphs`.
0.3.1
Added - update: some docstrings were improved - update: the README.md / Pypi Description file.
Fixed - Python 2 and 3 compatibility problem with scikit-learn (using version 0.20.1 from now on) - PyPi: setup.py: `long_description_content_type` set to `'text/markdown'`