Texplain

What's Changed
* Overhaul by tdegeus in https://github.com/tdegeus/texplain/pull/21
* Adding documentation by tdegeus in https://github.com/tdegeus/texplain/pull/22
* Adding formatting tool by tdegeus in https://github.com/tdegeus/texplain/pull/25


**Full Changelog**: https://github.com/tdegeus/texplain/compare/v0.3.4...v0.4.0

* Allowing empty directory (17)
* Fixing bug: allowing "." in citation key (16)
* Compliance with pep8 (12)

* Bugfix: allow run from folder of the TeX.
* Improved naming: by default the TeX is rename "main.tex" (if is does not exist).

* Minor bugfixes
* Removing whitespaces from bib-file

* Switching to Python module
* Adding test and CI
* Removing several CL options