fix(core_test): Sync with update_engine's new dbus API.
fix(core_test): Sync with update_engine's new dbus API.

Use -status instead of whatever the url option does/did.

Just drop the dbus test for now, I tried to switch to calling GetStatus
but didn't get it working and I need to get this in and tag a release...

coreos/coretest,coreos/coretest