Deprecated iteritems() method not forward-compatible with Python 3

[xenophonf]

Formulas iterating over dictionaries should use the items() method instead of iteritems() because the latter method has been removed from Python 3. While the items() method in Python 2 uses more memory than iteritems(), these dictionaries are typically small (e.g., sets of settings from Pillar).

[themalkolm]

@xenophonf, does salt support python 3?

[xenophonf]

I don't know if it does yet, but there's been talk about ongoing porting efforts as recently as May.