Fix AppVeyor build
Fix AppVeyor build

Reviewed By: gabelevi

Differential Revision: D9144670

fbshipit-source-id: c27f93ca6451900d027efbc66832f564e653045a

mroch/flow,gabelevi/flow,JonathanUsername/flow,facebook/flow,facebook/flow,jamesgpearce/flow,gabelevi/flow,facebook/flow,AgentME/flow,facebook/flow,mroch/flow,nmote/flow,popham/flow,popham/flow,jamesgpearce/flow,JonathanUsername/flow,samwgoldman/flow,jamesgpearce/flow,mroch/flow,facebook/flow,samwgoldman/flow,popham/flow,samwgoldman/flow,popham/flow,JonathanUsername/flow,jamesgpearce/flow,gabelevi/flow,gabelevi/flow,gabelevi/flow,mroch/flow,jamesgpearce/flow,popham/flow,JonathanUsername/flow,nmote/flow,nmote/flow,facebook/flow,mroch/flow,JonathanUsername/flow,nmote/flow,samwgoldman/flow,samwgoldman/flow,JonathanUsername/flow,nmote/flow,jamesgpearce/flow,mroch/flow,JonathanUsername/flow,gabelevi/flow,popham/flow,AgentME/flow,nmote/flow,jamesgpearce/flow,AgentME/flow,AgentME/flow,samwgoldman/flow,samwgoldman/flow,popham/flow,gabelevi/flow,facebook/flow,AgentME/flow,mroch/flow,nmote/flow