Update s3 integ tests to be less fragile

The two tests here will sometimes will due to mtime checks
triggering a sync.  We're really just interested in testing the
sync based on filename comparisons for these two tests so we're
now setting the mtime to 5 minutes in the past to avoid this issue.
Fix grammar
Merge branch 'fix-s3-integ-test' into develop

* fix-s3-integ-test:
  Fix grammar
  Update s3 integ tests to be less fragile