GitLab

* add python examples to test [test should fail]

* fix example && move some to advanced_example

* fix last line

* refine test python version

* fixed capital letters and formating

* fixed CMake capital letters; added VS 2013 to the list of allowed versions

* Update Python-API.md

* for a better jump in page

A space is needed between `#` and the headers content according to Github's markdown format [guideline](https://guides.github.com/features/mastering-markdown/)

After adding the spaces, we can jump to the exact position in page by click the link.

* fixed something mentioned by @wxchan

* Update Python-API.md

* Add examples on how to use the saved model

* move 'load model' examples to advanced_example

* add plot importance

* add plot example