Replace the deprecated SortedDict with pythons OrderedDict

From django 1.7 the class "django.utils.datastructures.SortedDict" is deprecated and the same will be removed from V1.9 since the class "collections.OrderedDict" is added in python 2.7 and latter.

In our horizon we are using the sorteddict in very decent number of times.
Since it is deprecated, our horizon code also should avoid the sorteddict class and start using the ordereddict class.

This blueprint will remove the sorteddict with the ordereddict.