publishing.md

1. Set the new version in the weaviate/version.py and test/test_version.py.
2. Run all tests. (Check test/README.md)
3. Then build the new package:
   python setup.py sdist bdist_wheel
4. And check it:
   twine check dist/*
5. Check if you are on correct GitBranch.
6. Commit the most current version to GitHub if this has not been done yet.
7. Check TravisCI status to be OK!, if not OK! fix it.
8. Give the commit of the current version a proper tag:
   git tag -a '<your tag>' -m '<some message for the tag>' && git push --tags tags are either in the form of v0.2.5 or v0.2.5rc0.
9. Optional: install package locally by running pip install . and check if the version is set correctly.
10. Finally publish:
    twine upload dist/*