Upgrade to GitHub-native Dependabot

Author: dependabot-preview[bot]

.github/dependabot.yml

@@ -0,0 +1,52 @@
+version: 2
+updates:
+- package-ecosystem: nuget
+  directory: "/"
+  schedule:
+    interval: daily
+    time: "10:00"
+  open-pull-requests-limit: 10
+  ignore:
+  - dependency-name: Microsoft.AspNetCore.App
+    versions:
+    - "> 2.1.6"
+  - dependency-name: AutoFixture.Xunit2
+    versions:
+    - 4.15.0
+    - 4.16.0
+  - dependency-name: AutoFixture.AutoMoq
+    versions:
+    - 4.15.0
+    - 4.16.0
+  - dependency-name: AutoFixture
+    versions:
+    - 4.15.0
+    - 4.16.0
+  - dependency-name: System.IO.Abstractions
+    versions:
+    - 13.2.10
+    - 13.2.11
+    - 13.2.15
+    - 13.2.17
+    - 13.2.20
+    - 13.2.23
+    - 13.2.24
+    - 13.2.25
+    - 13.2.28
+    - 13.2.9
+  - dependency-name: Microsoft.AspNetCore.SignalR.Protocols.MessagePack
+    versions:
+    - 5.0.2
+    - 5.0.3
+    - 5.0.4
+  - dependency-name: Microsoft.NET.Test.Sdk
+    versions:
+    - 16.8.3
+    - 16.9.1
+  - dependency-name: Octokit
+    versions:
+    - 0.48.0
+    - 0.49.0
+  - dependency-name: Moq
+    versions:
+    - 4.16.0