Remove unnecesary imports

samples/SampleStartups/project.json

@@ -8,12 +8,6 @@
   },
   "frameworks": {
     "net451": {},
-    "netcoreapp1.0": {
-      "imports": [
-        "dnxcore50",
-        "portable-net451+win8"
-      ],
-      "dependencies": {}
-    }
+    "netcoreapp1.0": {}
   }
 }

src/Microsoft.AspNetCore.Hosting/project.json

@@ -66,10 +66,7 @@
         "System.Console": "4.0.0-*",
         "System.Diagnostics.StackTrace": "4.0.1-*",
         "System.Reflection.Extensions": "4.0.1-*"
-      },
-      "imports": [
-        "portable-net45+win8"
-      ]
+      }
     }
   }
 }

src/Microsoft.AspNetCore.TestHost/project.json

@@ -33,10 +33,7 @@
       "dependencies": {
         "System.Diagnostics.Contracts": "4.0.1-*",
         "System.Net.Http": "4.1.0-*"
-      },
-      "imports": [
-        "portable-net45+win8"
-      ]
+      }
     }
   }
 }