[hack] Make ServerArgs.options an abstract type
[hack] Make ServerArgs.options an abstract type

Summary:Because we can (we probably didn't in the past due to code sharing between Hack
and Flow)

Reviewed By: andrewjkennedy

Differential Revision: D3056197

fb-gh-sync-id: c937959b0e5c27598afc20fec59aed1d7321eb0b
shipit-source-id: c937959b0e5c27598afc20fec59aed1d7321eb0b

d14b3l/flow,AgentME/flow,jdelStrother/flow,popham/flow,fletcherw/flow,popham/flow,claudiopro/flow,jgrund/flow,nmote/flow,gabro/flow,ForbesLindesay/flow,claudiopro/flow,claudiopro/flow,jdelStrother/flow,gabelevi/flow,d14b3l/flow,jeffmo/flow,jeffmo/flow,cesarandreu/flow,AgentME/flow,jeffmo/flow,gabelevi/flow,ForbesLindesay/flow,jamesgpearce/flow,popham/flow,chenglou/flow,ForbesLindesay/flow,JonathanUsername/flow,chenglou/flow,ylu1317/flow,fletcherw/flow,jeffmo/flow,facebook/flow,facebook/flow,popham/flow,fletcherw/flow,fletcherw/flow,TiddoLangerak/flow,TiddoLangerak/flow,jdelStrother/flow,fletcherw/flow,ForbesLindesay/flow,facebook/flow,jamesgpearce/flow,MichaelDeBoey/flow,nmote/flow,gabelevi/flow,TiddoLangerak/flow,gabelevi/flow,facebook/flow,nmote/flow,AprilArcus/flow,nmote/flow,samwgoldman/flow,gabro/flow,ylu1317/flow,popham/flow,claudiopro/flow,samwgoldman/flow,mroch/flow,AprilArcus/flow,nmote/flow,jeffmo/flow,ForbesLindesay/flow,d14b3l/flow,claudiopro/flow,cesarandreu/flow,AgentME/flow,d14b3l/flow,jgrund/flow,jgrund/flow,JonathanUsername/flow,AprilArcus/flow,JonathanUsername/flow,jdelStrother/flow,samwgoldman/flow,gabelevi/flow,ylu1317/flow,jamesgpearce/flow,MichaelDeBoey/flow,gabelevi/flow,MichaelDeBoey/flow,TiddoLangerak/flow,gabro/flow,fletcherw/flow,JonathanUsername/flow,jeffmo/flow,mroch/flow,chenglou/flow,chenglou/flow,gabelevi/flow,chenglou/flow,jdelStrother/flow,jamesgpearce/flow,JonathanUsername/flow,JonathanUsername/flow,jamesgpearce/flow,chenglou/flow,nmote/flow,mroch/flow,AprilArcus/flow,AgentME/flow,MichaelDeBoey/flow,jgrund/flow,jgrund/flow,nmote/flow,AprilArcus/flow,popham/flow,JonathanUsername/flow,TiddoLangerak/flow,facebook/flow,mroch/flow,samwgoldman/flow,facebook/flow,gabro/flow,samwgoldman/flow,AgentME/flow,jamesgpearce/flow,gabro/flow,jgrund/flow,gabro/flow,mroch/flow,ForbesLindesay/flow,MichaelDeBoey/flow,ylu1317/flow,samwgoldman/flow,d14b3l/flow,facebook/flow,AprilArcus/flow,cesarandreu/flow,jdelStrother/flow,jamesgpearce/flow,cesarandreu/flow,mroch/flow,popham/flow,d14b3l/flow,mroch/flow,ylu1317/flow,samwgoldman/flow