Add openapi3 & servant-openapi3
Add openapi3 & servant-openapi3

Daniel-Diaz/stackage,michalkonecny/stackage,mrkkrp/stackage,iand675/stackage,jonschoning/stackage,simonmichael/stackage,fpco/stackage,massysett/stackage,clinty/stackage,soenkehahn/stackage