* This patch adds a utility that helps serialize data into a JSON
string that might contain some non-standard data types like
generators iterators and frozen dicts coming from YAQL. The
utility uses oslo.serialization project that already takes care
of iterators and any kinds of custom dicts. And in addition, it
handles generators (assuming a generator represents an iterable
similar to an iterator).
* Unit tests.
* Added YAQL into requirements and bumped the version of
oslo.serialization to make sure to have the "fallback" parameter