Modify MutationEvent test to ensure constructor throws
Modify MutationEvent test to ensure constructor throws

MutationEvent has no public constructor, so this should always throw.

snuggs/jsdom,Joris-van-der-Wel/jsdom,mzgol/jsdom,Sebmaster/jsdom,Sebmaster/jsdom,tmpvar/jsdom,mzgol/jsdom,mbostock/jsdom,Zirro/jsdom,nicolashenry/jsdom,fiftin/jsdom,Zirro/jsdom,snuggs/jsdom,fiftin/jsdom,mzgol/jsdom,Joris-van-der-Wel/jsdom,nicolashenry/jsdom,Sebmaster/jsdom,mbostock/jsdom,Joris-van-der-Wel/jsdom,nicolashenry/jsdom,tmpvar/jsdom,fiftin/jsdom,mbostock/jsdom