Adds official .NET 5 support (#300)

.github/workflows/build-test.yml

@@ -0,0 +1,33 @@
+name: Build
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: macos-latest
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0 # avoid shallow clone so nbgv can do its work.
+    - name: Setup .NET 5
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: 5.0.100-rc.2.20479.15
+    - name: Restore NuGet Packages
+      run: dotnet restore --force-evaluate
+    - name: Build Server
+      run: dotnet build -c Release -f net5.0 --no-restore Projects/Server/Server.csproj
+    - name: Build UO Content
+      run: dotnet build -c Release -f net5.0 --no-restore Projects/UOContent/UOContent.csproj
+    - name: Test
+      run: dotnet test --no-restore -f net5.0