Remove duplication

src/ImageSharp/project.json

@@ -31,22 +31,22 @@
     "StyleCop.Analyzers": {
       "version": "1.0.0",
       "type": "build"
-    }
+    },
+    "System.Buffers": "4.0.0",
+    "System.Numerics.Vectors": "4.1.1",
+    "System.Runtime.CompilerServices.Unsafe": "4.0.0"
   },
   "frameworks": {
     "netstandard1.1": {
       "dependencies": {
-        "System.Buffers": "4.0.0",
         "System.Collections": "4.0.11",
         "System.Diagnostics.Debug": "4.0.11",
         "System.Diagnostics.Tools": "4.0.1",
         "System.IO": "4.1.0",
         "System.IO.Compression": "4.1.0",
         "System.Linq": "4.1.0",
-        "System.Numerics.Vectors": "4.1.1",
         "System.ObjectModel": "4.0.12",
         "System.Resources.ResourceManager": "4.0.1",
-        "System.Runtime.CompilerServices.Unsafe": "4.0.0",
         "System.Runtime.Extensions": "4.1.0",
         "System.Runtime.InteropServices": "4.1.0",
         "System.Runtime.Numerics": "4.0.1",
@@ -58,9 +58,6 @@
     },
     "net45": {
       "dependencies": {
-        "System.Buffers": "4.0.0",
-        "System.Numerics.Vectors": "4.1.1",
-        "System.Runtime.CompilerServices.Unsafe": "4.0.0"
       },
       "frameworkAssemblies": {
         "System.Runtime": ""