Dedupe

- fixed bug that was preventing learning of index predicates in Dedupe mode

- Improved memory performance of connected components

- Python 3 only
- Static typing and type Hints
- Incorporate sqlite to extend normal API to millions of records
- Multiprocessing enabled for Windows
- Multiprocessing mode changed to spawn for Mac OS X
- Moved from CamelCase to lowercase_with_underscore for method names.
- Dropped ability to save indices in save settings.
- Moved from Deduper.match -> Dedupe.partition, RecordLink.match -> RecordLink.join, Gazetteer.match -> Gazetteer.search
- Renamed Matching.blocker -> Matching.fingerprinter
- Moved to autodoc for documentation
- Dropped threshold methods
- matchBlocks has been replaced by score, which takes pairs of records not blocks

- Dropped python 2.7 support

- Cleaned up block learning

- Improved performance of connected components algorithm with very large components
- Fixed pickling unpickling bug of Index predicate classes