v0.2.0

drive: case around upload stall

The upload stall budget now assumes a 100 KB/s floor instead of 200
KB/s. On a slow uplink the previous value could exhaust the six
in-process attempts on a multi-gigabyte file, even though each attempt
resumed from the last byte. The cost is a longer wait on a genuine
stall, which keepalive already catches when the peer is dead.

Signed-off-by: Rohit Yadav <rohit@scaleninja.com>