the System.Runtime.InteropServices.PInvoke it's not needed

Author: enricosada

tests/fsharp/project.json

@@ -24,7 +24,6 @@
     "System.Runtime": "4.1.0",
     "System.Runtime.Extensions": "4.1.0",
     "System.Runtime.InteropServices": "4.1.0",
-    "System.Runtime.InteropServices.PInvoke": "4.0.0-rc2-24027",
     "System.Runtime.Loader": "4.0.0",
     "System.Runtime.Numerics": "4.0.1",
     "System.Security.Cryptography.Algorithms": "4.2.0",