
Show progress meter for fetches when `stdout` is a `tty`. * fetch_strategy.py: show progress * "Fetched: x MB at y MB/s" * add tests, show % if content-length
Show progress meter for fetches when `stdout` is a `tty`. * fetch_strategy.py: show progress * "Fetched: x MB at y MB/s" * add tests, show % if content-length