0.2.0

This release introduces the following changes:

• Merge ProceduralRule class with Rule
• Split aspects of Rule into a separate Holding class
• Use Selectors to anchor Holdings to Opinion text
• Ignore was/were differences in Predicate content text
• Let input JSON label a Rule as the "exclusive" way to get output
• Create addition operator for Factors, Rules, and Holdings
• Let Rule init method handle the necessary Procedure init method
• Use addition operator to add Factors as Rule inputs
• Use addition operator to add Enactments to Rules
• Create function to consolidate list of Enactments
• Add Union operator for Rules and Holdings
• Move functions for loading objects from JSON and XML to new I/O modules
• Add "explain" functions to show how generic Factors match up when a contradiction or implication exists
• Add whitespace to __str__ methods for greater clarity