swift: trial icehouse upgrade in esams

The idea behind the pinning is being able to run "apt-get install swift"
whenever upgrading a box and have apt figure out that all of its dependencies
must come from icehouse, thus needs to be higher than origin "wikimedia" pinned
at 1001. Rollback is to remove the preference/pinning and run "apt-get install
swift" again to have the packages downgraded.

Change-Id: I8d86bef9d1191f09f28dba94d1886100ce75199f