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

cyborg/db/sqlalchemy/api.py

@@ -273,7 +273,7 @@ def deployable_get_by_filters_with_attributes(self, context,
                                     'accelerator_id']
         attribute_filters = {}
         filters_copy = copy.deepcopy(filters)
-        for key, value in filters_copy.iteritems():
+        for key, value in filters_copy.items():
             if key not in exact_match_filter_names:
                 # This key is not in the deployable regular fields
                 value = filters.pop(key)