Fix master tests in Relay OSS, really
Fix master tests in Relay OSS, really

Summary: I actually fixed this in two ways, first by adding a `setImmediate` shim (which worked) and then by switching to `resolveImmediate` (which didn't work, but I failed to adequately test this). It seems the tests are very sensitive, with their use of `jest.run{All,OnlyPending}Timers`.

Third time lucky; let's just use `setTimeout`, which should be fine as this is just the test suite.
Closes https://github.com/facebook/relay/pull/513

Reviewed By: josephsavona

Differential Revision: D2579979

fb-gh-sync-id: 888021c83e2cef41ac27e44597888b45d88ba91f

atxwebs/relay,mroch/relay,forter/generic-relay,zpao/relay,wincent/relay,kassens/relay,chirag04/relay,dbslone/relay,wincent/relay,chentsulin/relay,kassens/relay,benjaminogles/relay,xuorig/relay,atxwebs/relay,michaelchum/relay,josephsavona/relay,cesarandreu/relay,michaelchum/relay,iamchenxin/relay,NevilleS/relay,xuorig/relay,wincent/relay,cpojer/relay,josephsavona/relay,venepe/relay,yungsters/relay,atxwebs/relay,cpojer/relay,freiksenet/relay,voideanvalue/relay,NevilleS/relay,chentsulin/relay,benjaminogles/relay,Aweary/relay,venepe/relay,xuorig/relay,gabelevi/relay,Aweary/relay,xuorig/relay,chirag04/relay,kassens/relay,zpao/relay,NevilleS/relay,dbslone/relay,gabelevi/relay,heracek/relay,atxwebs/relay,Aweary/relay,josephsavona/relay,mroch/relay,voideanvalue/relay,freiksenet/relay,facebook/relay,zpao/relay,rosskevin/relay,cesarandreu/relay,chentsulin/relay,rosskevin/relay,andimarek/generic-relay,facebook/relay,iamchenxin/relay,gabelevi/relay,venepe/relay,wincent/relay,kassens/relay,cpojer/relay,kassens/relay,xuorig/relay,xuorig/relay,wincent/relay,voideanvalue/relay,andimarek/generic-relay,cpojer/relay,kassens/relay,andimarek/generic-relay,apalm/relay,yungsters/relay,heracek/relay,facebook/relay,freiksenet/relay,benjaminogles/relay,facebook/relay,voideanvalue/relay,facebook/relay,mroch/relay,facebook/relay,voideanvalue/relay,yungsters/relay,apalm/relay,chirag04/relay,voideanvalue/relay,iamchenxin/relay,iamchenxin/relay,wincent/relay,cesarandreu/relay,heracek/relay,apalm/relay,michaelchum/relay