Before this change we didn't calculate any hashes for test files
created in the Run framework.
This means that files were uploaded to S3 without a `Content-MD5`
header. This in turn caused minio to disengage `--compat` mode which
in turn caused the `TestSyncAfterChangingModtimeOnlyWithNoUpdateModTime`
test to fail in `fs/sync`.
After this change we supply all hashes supported by the destination Fs
on the upload object.
This means that the `Content-MD5` is set and minio engages `--compat`
mode to fix the problem. Using `--compat` on the command line also
fixes the problem.
This much better replicates how objects are actually uploaded with
operations.Copy so should improve the integration tests.
Nick Craig-Wood
66347aff2a