PY3 : Replice dict.iteritems() with dict.items()
PY3 : Replice dict.iteritems() with dict.items()

py3 tests for cyborg are failing due to
dict.iteritems() which has been removed in python 3 [1].
This patch replaces that usage with dict.items,
which also works in python 2.7, as recommended.

[1] https://wiki.python.org/moin/Python3.0#Built-In_Changes

Change-Id: Ic23c0c09b346cb59344828e8189036306072e040

openstack/nomad