v0.4.0

• Adds _check_adcid method to validate a provided ADCID against current list of ADCIDs. (Actual validation should be implemented by overriding the is_valid_adcid method in Datastore class)
• Adds get_previous_record method to grab previous record from Datastore, which can grab the previous record or the previous record where a specific field is non-empty
• Adds support for comparing against the previous record in compare_with
• Adds new rule compare_age to handle rules that need to compare ages relative to a date
• Adds custom operator count_exact to json_logic.py
• Updates _check_subschema_valid to accept an optional record parameter, defaults to the document - used for rules that require the previous record
• Updates _validate_compute_gds to remove partial GDS score calculation
• Updates _validate_compare_with to support the abs operator
• Updates _validate_compatibility error message to be more verbose
• Updates _validate_temporalrules to also support ignore_empty and swap_order parameters
• Refactors the tests to be more modularized so that they're more manageable
• Refactors logic for compare_values by moving it to its own utility method and allows comparing to null values
• Fixes issue where datastore was not being set for the temp validator in _check_subschema_valid, causing nested conditions with previous records to not evaluate correctly