Update to fetch destination docs based on identity fields, not
timestamp. Change comparisonExclusionFields field name in
migrationConfiguration.json to comparisonExclusionFields for
naming/description consistency. Fixes #44
Add ability to filter source and destination docs before comparing. Fixes #45
Merge pull request #48 from derek63/fixfetchlogic

Correct fetch & compare logic
Only functional update is to get source config (not destination) when loading source data
Merge pull request #50 from jewzaam/job-fix

Only functional update is to get source config (not destination) when loading source data