Added travis ci support and replaced distutils with setuptools
add installing pygraphviz in travis.yml
corrected install section for travis
try pip freeze
try pip freeze
try pip freeze
changed way to look for _graphviz.so (search inside site path instead of local path)
try pip freeze
extended locations to look for _graphviz.so
Added coveralls
fixed coverage test run
Merge pull request #1 from mmarkov/implement-travis-ci

Implement travis ci