v0.4.79

Transducers v0.4.79

Diff since v0.4.78

Merged pull requests:

• improve GroupBy documentation and remove some more old julia version support (#20) (@ExpandingMan)
• Make Cat() support asfoldable (#24) (@MasonProtter)

Closed issues:

• get method for GroupByViewDict is broken (#15)
• GroupByViewDict missing a halve method (#16)
• Erroring inconsistency with Cat and a reducible defined via as foldable vs __foldl__ (#23)