added leftT and improved existing lift API for EitherT#1614

Merged

kailuowang merged 2 commits intotypelevel:masterfrom kailuowang:new-eitherT-factories

Apr 24, 2017

+94-14

Commits on Apr 18, 2017

added leftT and improved existing creation API for EitherT
kailuowang
committed

Commits on Apr 20, 2017

added fromOptionF
kailuowang
committed