Storj has a rate limit of 1 per second when uploading to the same
file.
This was being tripped by the integration tests.
This patch fixes it by detecting the error and sleeping for 1 second
before retrying.
See: https://github.com/storj/uplink/issues/149
The "relative" argument was missing when Put'ing a file. This
sets an incorrect object entry in the cache, leading to the file being
unreadable when using mount functionality.
Fixes#6151
