Neo4jRtStore Implemented

[mrw8]

Major Changes

• Removed transaction management from TupleInsertionVisitor and added it to Neo4jRtStore
• Added TransactionManager class to handle the opening and closing of transactions for a Neo4j database
• Implemented save_tuple, get_tuple, get_by_referent, get_by_author, get_available_rui, get_by_referents_by_type_and_designator_type, and run_query in Neo4jRtStore
• Added testing for the above functions except for run_query
• Expanded Neo4jEntryConverter to work for more datatypes

Minor Changes

• Added build_condition and build_where helper functions for run_query
• Implemented Neo4jTupleConverter
• Changed names of attributes for some tuplenodes from rui to uri or uui depending on the node.
• Edited testing print statements to be more informative