Adjusted travis to test for python 3 as well
Adjusted travis to test for python 3 as well

manasdk/GitPython,jeblair/GitPython,dpursehouse/GitPython,bwrsandman/GitPython,roidelapluie/GitPython,zsjohny/GitPython,StyXman/GitPython,cdht/GitPython,bwrsandman/GitPython,gitpython-developers/GitPython,gitpython-developers/gitpython,StyXman/GitPython,nvie/GitPython,avinassh/GitPython,jeblair/GitPython,pengshp/GitPython,cdht/GitPython,gitpython-developers/GitPython,nvie/GitPython,beni55/GitPython,hvnsweeting/GitPython,bwrsandman/GitPython,avinassh/GitPython,pengshp/GitPython,dpursehouse/GitPython,zsjohny/GitPython,breavo/GitPython,expobrain/GitPython,pengshp/GitPython,breavo/GitPython,StyXman/GitPython,roidelapluie/GitPython,ghtdak/GitPython,expobrain/GitPython,gitpython-developers/gitpython,manasdk/GitPython,avinassh/GitPython,cdht/GitPython,ghtdak/GitPython,hvnsweeting/GitPython,h4ck3rm1k3/GitPython,h4ck3rm1k3/GitPython,zsjohny/GitPython,beni55/GitPython