Add typehint to setting workflow configuration
Add typehint to setting workflow configuration

Test Plan: This diff.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D4784

folsom-labs/arcanist,alexmv/arcanist,memsql/arcanist,wharris/arcanist,coursera/arcanist,r4nt/arcanist,wikimedia/phabricator-arcanist,jra3/arcanist,jra3/arcanist,aik099/arcanist,calblueprint/arcanist,alexmv/arcanist,r4nt/arcanist,dguo-coursera/arcanist,wxstars/arcanist,jra3/arcanist,julkiewicz/arcanist,zhihu/arcanist,wharris/arcanist,chundongwang/arcanist,wikimedia/phabricator-arcanist,fivestars/arcanist,haskell-infra/arcanist,codelabs-ch/arcanist,julkiewicz/arcanist,codelabs-ch/arcanist,phacility/arcanist,eSpark/arcanist,chundongwang/arcanist,PageUpPeopleOrg/arcanist-patches,sneakpeeq/arcanist,r4nt/arcanist,codelabs-ch/arcanist,julkiewicz/arcanist,kevinseelbach/arcanist,memsql/arcanist,dguo-coursera/arcanist,calblueprint/arcanist,hach-que/arcanist,Khan/arcanist,zhihu/arcanist,phacility/arcanist,aik099/arcanist,r4nt/arcanist,folsom-labs/arcanist,chundongwang/arcanist,Symplicity/arcanist,haskell-infra/arcanist,Symplicity/arcanist,hach-que/arcanist,kevinseelbach/arcanist,zhihu/arcanist,PageUpPeopleOrg/arcanist-patches,Khan/arcanist,hach-que/arcanist,dguo-coursera/arcanist,fivestars/arcanist,wharris/arcanist,kevinseelbach/arcanist,uber/arcanist,phacility/arcanist,PageUpPeopleOrg/arcanist-patches,PageUpPeopleOrg/arcanist-patches,sneakpeeq/arcanist,eSpark/arcanist,coursera/arcanist,Symplicity/arcanist,hach-que/arcanist,codelabs-ch/arcanist,julkiewicz/arcanist,folsom-labs/arcanist,coursera/arcanist,calblueprint/arcanist,kevinseelbach/arcanist,eSpark/arcanist,Symplicity/arcanist,memsql/arcanist,wxstars/arcanist,alexmv/arcanist,wxstars/arcanist,uber/arcanist,wikimedia/phabricator-arcanist,alexmv/arcanist,phacility/arcanist,aik099/arcanist,chundongwang/arcanist,KieranHayes/arcanist,sneakpeeq/arcanist,haskell-infra/arcanist,codelabs-ch/arcanist,phacility/arcanist,eSpark/arcanist,dguo-coursera/arcanist,sneakpeeq/arcanist,KieranHayes/arcanist,fivestars/arcanist,uber/arcanist,uber/arcanist,wikimedia/phabricator-arcanist,jra3/arcanist,aik099/arcanist,KieranHayes/arcanist,folsom-labs/arcanist,fivestars/arcanist,Khan/arcanist,Khan/arcanist,zhihu/arcanist,calblueprint/arcanist,wxstars/arcanist,coursera/arcanist,haskell-infra/arcanist,wharris/arcanist,memsql/arcanist,KieranHayes/arcanist