[enh] add setup.cfg for releasing
[enh] same with MANIFEST.in
[mod] fix dependancy in setup.py because baron 0.4 will have a little format change
[mod] let's try some hack to only build against master of baron in travis if the branch isn't master
[doc] update installation procedure
[enh] add a CHANGELOG
[enh] handle long description in the README.md using pypandoc trick
[mod] add some keywords
[doc] add classifiers in setup.py