0.0.1.dev7 (from datatest 0.9.2)

• Changed Query class:
  • Added flatten() method to serialize dictionary results.
  • Added to_csv() method to quickly save results as a CSV file.
  • Changed reduce() method to accept "initializer_factory" as
    an optional argument.
  • Changed filter() method to support predicate matching.
• Added True and False as predicates to support "truth value testing" on
  arbitrary objects (to match on truthy or falsy).
• Changed Selector class keyword filtering to support predicate matching.