v0.2.8

Folds v0.2.8

Diff since v0.2.7

Merged pull requests:

• Use ExternalDocstrings (#47) (@tkf)
• Use tkf/julia-code-style-suggesters@v1 (#49) (@tkf)
• Fix findmax etc. (#50) (@tkf)
• Fix Folds.dict(array) (#51) (@tkf)