since it has been passing my test run; i'll land it and mark it as unstable.
Mark staging tests that pass 10+ time in a row as stable tests
This PR is mostly for implementing "fixture" for nightly test. Note that the current fixture implementation is not that great, and we can probably improve this in the future after refactoring e2e.py.
* Done initial stage. * lint * . * Finished. * Fix lint
