Travis: Excluding UndefinedBehaviorSanitizer for macOS due to link errors
Travis: Excluding UndefinedBehaviorSanitizer for macOS due to link errors

https://travis-ci.org/libexpat/libexpat/jobs/556567990#L529

libexpat/libexpat,libexpat/libexpat,libexpat/libexpat,libexpat/libexpat,libexpat/libexpat,libexpat/libexpat