A try to use pull request  :  The little change in sina.py

I just change a little docstring in sina.py , home_timeline() method.
This time is just a try, so I want your opinions.After recieving your suggestion, I will finish the other part.
Is there any errors or bugs?
And I am not sure that I use git command in the right way.I use master branch.

PS.There are also some changes of *.rst doc,not in the doc directory.I still do not find the way to use make.sh, and I can not find the index.html.To render the html,I copy the *.rst to the outer directory and use command just like"sphinx-quickstart""make html" etc.