Fix for DefaultSnapshotRemoverIT

The IT depends on file timestamp of checked out sources. This is
why it never fails on CI, as there is always freshly checked out.

On dev machine on the other hand, if the git repo was checked out
2+ ago, this IT will start failing.

fix is to not preserve timestamps on fillInRepo().
Merge pull request #890 from sonatype/DefaultSnapshotRemoverIT-fix

Fix for DefaultSnapshotRemoverIT
Merge remote-tracking branch 'origin/master' into NEXUS-7292-scheduler-rework