use Microsoft.NETCore.Runtime.CoreCLR instead of metapackage Microsoft.NETCore.Runtime (prerelease)

the "Microsoft.NETCore.Runtime": "1.0.2-rc4-24201-00" was downgraded to -rc2 anyway during restore

Author: enricosada

tests/fsharp/project.json

@@ -1,7 +1,6 @@
 {
   "dependencies": {
     "Microsoft.NETCore.Platforms": "1.0.1",
-    "Microsoft.NETCore.Runtime": "1.0.2-rc4-24201-00",
     "NETStandard.Library": "1.6.0",
     "System.Collections": "4.0.11",
     "System.Collections.Immutable":"1.2.0",
@@ -38,7 +37,7 @@
     "Microsoft.DiaSymReader.PortablePdb": "1.1.0",
     "Microsoft.DiaSymReader": "1.0.8",
 
-    "Microsoft.NETCore.Runtime.CoreCLR": "1.0.2-rc2-24027", 
+    "Microsoft.NETCore.Runtime.CoreCLR": "1.0.2", 
     "Microsoft.NETCore.TestHost": "1.0.0", 
     "System.Reflection.Emit.ILGeneration": "4.0.1",
     "System.Security.Cryptography.Primitives": "4.0.0"