Updated the Xunit.Extensions dependency version
Updated the Xunit.Extensions dependency version

for AutoFixture.Xunit, because the actual AutoFixture.Xunit library is
compiles against Xunit.Extensions 1.8.0.1549, so the NuGet package ought
to reflect that correctly.

dlongest/AutoFixture,hackle/AutoFixture,sbrockway/AutoFixture,amarant/AutoFixture,yuva2achieve/AutoFixture,Pvlerick/AutoFixture,dcastro/AutoFixture,olegsych/AutoFixture,adamchester/AutoFixture,sergeyshushlyapin/AutoFixture,sean-gilliam/AutoFixture,olegsych/AutoFixture,AutoFixture/AutoFixture,hackle/AutoFixture,StevenJiang2015/AutoFixture,adamchester/AutoFixture,dcastro/AutoFixture,zvirja/AutoFixture,dlongest/AutoFixture,mrinaldi/AutoFixture,sbrockway/AutoFixture,amarant/AutoFixture,StevenJiang2015/AutoFixture,mrinaldi/AutoFixture,yuva2achieve/AutoFixture,sergeyshushlyapin/AutoFixture