Remove Object.assign() from parser tests
Remove Object.assign() from parser tests

Summary:
Older versions of node didn't like it. Tested this change with Node v0.10.26
and v4.1.2
Closes https://github.com/facebook/flow/pull/1218

Reviewed By: svcscm

Differential Revision: D2790295

Pulled By: gabelevi

fb-gh-sync-id: d1f58b19118d47f88cdbfbde05eae483b5968159

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