Update README to use Travis information for BinetReseau/Kaoz repository

Signed-off-by: Nicolas Iooss <nicolas.iooss_git@polytechnique.org>
Rename tests/ssl to tests/certs

This fix a failing Python 3.3 test due to a bad behaviour of "import ssl" in tests directory

Signed-off-by: Nicolas Iooss <nicolas.iooss_git@polytechnique.org>