Cache nuget packages (#53)

* Cache nuget packages

* Use lockfile to restore packages

* Use build props

Author: ErikSchierboom

.github/workflows/ci.yml

@@ -23,7 +23,12 @@ jobs:
       - name: Setup .NET
         uses: actions/setup-dotnet@3951f0dfe7a07e2313ec93c75700083e2005cbab
         with:
-          dotnet-version: 5.0.202
+          dotnet-version: "5.0.202"
+          cache: true
+          cache-dependency-path: "**/packages.lock.json"
+
+      - name: Restore packages
+        run: dotnet restore --locked-mode
 
       - name: Run tests
         run: dotnet test

Directory.Build.props

@@ -0,0 +1,5 @@
+<Project>
+  <PropertyGroup>
+    <RestorePackagesWithLockFile>true</RestorePackagesWithLockFile>
+  </PropertyGroup>
+</Project>