Tweak testing instructions
Tweak testing instructions

Summary: `Skipping directory` isn't in the test output, but `SKIP` is.
Closes https://github.com/facebook/flow/pull/1024

Reviewed By: svcscm

Differential Revision: D2605252

Pulled By: mroch

fb-gh-sync-id: 4abc0f7a3e23b459b7037cc6743907498bd968d9

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