Update cats, cats-effect and http4s versions#4

Merged

rossabaker merged 2 commits intogetnelson:masterfrom janschultecom:bumb-versions

Feb 22, 2019

+95-95

Commits on Jan 9, 2019

Update cats, cats-effect and http4s versions
janschultecom
committed

Commits on Jan 11, 2019

Remove unused dependencies
janschultecom
committed