safe with python 3: import StringIO, reduce, isinstance(, basestring)

Changed StringIO to BytesIO for python 3

made safe with python 3: StringIO, reduce, basestring
Added six to requirements.txt
Added python 3.3 testing to .travis.yml
Merge pull request #2 from andres-s/topy3

Python 3 support
Update .travis.yml

Python 3.2 and 3.4 added.
Update README.md

Note about Python 3 removed.
Update LICENSE.txt
Update README.md
Package updated