Remove direct Microsoft.NETCore.Platforms dependency.

- Microsoft.NETCore.App now pulls this package in.

aspnet/Coherence-Signed#344

samples/IdentitySample.Mvc/project.json

@@ -5,7 +5,6 @@
   "description": "Identity sample MVC application on ASP.NET Core",
   "version": "1.0.0-*",
   "dependencies": {
-    "Microsoft.NETCore.Platforms": "1.0.1-*",
     "Microsoft.AspNetCore.Mvc": "1.0.0-*",
     "Microsoft.AspNetCore.Mvc.TagHelpers": "1.0.0-*",
     "Microsoft.AspNetCore.DataProtection.Extensions": "1.0.0-*",

test/Microsoft.AspNetCore.Identity.EntityFrameworkCore.InMemory.Test/project.json

@@ -8,7 +8,6 @@
   },
   "dependencies": {
     "dotnet-test-xunit": "1.0.0-*",
-    "Microsoft.NETCore.Platforms": "1.0.1-*",
     "Microsoft.AspNetCore.Hosting": "1.0.0-*",
     "Microsoft.AspNetCore.Http": "1.0.0-*",
     "Microsoft.AspNetCore.Identity": "1.0.0-*",

test/Microsoft.AspNetCore.Identity.EntityFrameworkCore.Test/project.json

@@ -16,7 +16,6 @@
   },
   "dependencies": {
     "dotnet-test-xunit": "1.0.0-*",
-    "Microsoft.NETCore.Platforms": "1.0.1-*",
     "Microsoft.EntityFrameworkCore.InMemory": "1.0.0-*",
     "Microsoft.EntityFrameworkCore.SqlServer": "1.0.0-*",
     "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0-*",

test/Microsoft.AspNetCore.Identity.InMemory.Test/project.json

@@ -8,7 +8,6 @@
   },
   "dependencies": {
     "dotnet-test-xunit": "1.0.0-*",
-    "Microsoft.NETCore.Platforms": "1.0.1-*",
     "Microsoft.AspNetCore.Authentication": "1.0.0-*",
     "Microsoft.AspNetCore.Authentication.Cookies": "1.0.0-*",
     "Microsoft.AspNetCore.Hosting": "1.0.0-*",

test/Microsoft.AspNetCore.Identity.Test/project.json

@@ -8,7 +8,6 @@
   },
   "dependencies": {
     "dotnet-test-xunit": "1.0.0-*",
-    "Microsoft.NETCore.Platforms": "1.0.1-*",
     "Microsoft.AspNetCore.Hosting": "1.0.0-*",
     "Microsoft.AspNetCore.Http": "1.0.0-*",
     "Microsoft.AspNetCore.Identity": "1.0.0-*",