* [infra] Add support for dataflow builds to the helper script and build check (#1632).
* Update travis config file.
* Address self-review comments and specify dataflow sanitizer for zstd as well.
* Fix fuzzing_engines in project.yaml
* Fix bad build check for DFSan.
* Use "hasattr" in helper.py to check the sanitizer argument.
* Address more review comments.
* Remove DataFlow config from zstd.
* fix a typo