Release PyPi Instruction

Instruction to release pyclustering library to PyPi repository:

1. Check version in setup.py and update it if it is required.
2. Check DOI link (README.rst, PKG-INFO.rst) and update it if it is required.
3. Check description PKG-INFO.rst and update it if it is required.
4. Add core binaries to the library from cloud.
5. Create pypi file description:

$ touch ~/.pypirc
$ nano ~/.pypirc

6. Add following description:

[distutils]
index-servers=
    testpypi
    pypi

[testpypi]
repository = https://test.pypi.org/legacy/
username = <username>
password = <password>

[pypi]
repository = https://upload.pypi.org/legacy/
username = <username>
password = <password>

7. Check setup file:

$ python3 setup.py check -r -s

8. Create distributive:

$ python3 setup.py sdist

9. Upload to test repository:

$ twine upload dist/* -r testpypi

10. If everything is ok on test page then upload it to legacy:

$ twine upload dist/* -r pypi