Migrating asp.net core xUnit Tests from RC1 to RC2 running under net46/net452

TL;DR version:

All comes down to the project.json.

{
  "version" : "1.0.0-*",
  "buildOptions" : 
     { "preserveCompilation" : true }
  },
  "dependencies" : {
    "dotnet-test-xunit" : "1.0.0-rc2-*",
    "xunit" : "2.1.0-rc2-*",
    "Automapper: "4.2.1",
   },
   "frameworks" : {
     "net46" : {
        "dependencies" : {
        "ClassLibNet46" : {
            "target" : "project"
            }
         }
      }
   },
   "testRunner" : "xunit",
   "tooling" : {
       "defaultNamespace" : "RC2.ClassLibNet46"
   }
}