Add .travis.yml For now this is mainly useful if you work on a fork of the libxml2 mirror on GitHub: https://github.com/GNOME/libxml2 Start with two build setups: - GCC with as many GNU extensions disabled as possible, trying to emulate a C89 compiler on a POSIX system. - clang with ASan and UBSan. The Python tests don't set an exit code, so Travis won't detect failures. The same goes for "make tests", but we only run "make check" anyway.