enable CI

.github/workflows/build+test.yml

@@ -0,0 +1,23 @@
+name: Build + Test
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Setup .NET Core
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: 3.1.101
+    - name: Build
+      run: dotnet build --configuration Release
+    - name: Test
+      run: dotnet test --configuration Release

Codecs.sln

@@ -15,6 +15,11 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Python.Runtime.Codecs", "sr
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Codecs.Tests", "tests\Codecs.Tests.csproj", "{51EB80FB-59A6-4699-ACF0-F9BE6950E45B}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "CI", "CI", "{6CEA9133-ACDF-492D-BB26-21C356B4105E}"
+	ProjectSection(SolutionItems) = preProject
+		.github\workflows\build+test.yml = .github\workflows\build+test.yml
+	EndProjectSection
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU