* add a demo of multi-class classification R version
* add a demo of multi-class classification result
* add intro to the demo readme
* Delete train.md
* Update README.md
* Some minor changes to the code style
Some minor changes to the code style in file basic_walkthrough.py
* coding style changes
* coding style changes arrcording PEP8
* Update basic_walkthrough.py
* Fix minor typo
* Minor edits to coding style
Minor edits to coding style following the proposals of PEP8.