Bump CI to .NET 6

.github/workflows/dotnetcore.yml

@@ -13,10 +13,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Setup .NET Core
+    - name: Setup .NET
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: 3.1.101
+        dotnet-version: 6.0.x
     - name: Install dependencies
       run: dotnet restore
     - name: Build

global.json

@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "5.0",
+    "version": "6.0.0",
     "rollForward": "latestMajor",
     "allowPrerelease": false
   }