Add codecov.

build/test-all.ps1

@@ -7,7 +7,7 @@ $full = $args[0]
 foreach ($solutionPath in $solutionPaths) {    
     $solutionAbsPath = (Join-Path $rootFolder $solutionPath)
     Set-Location $solutionAbsPath
-    dotnet test --no-build --no-restore
+    dotnet test --no-build --no-restore --collect:"XPlat Code Coverage"
     if (-Not $?) {
         Write-Host ("Test failed for the solution: " + $solutionPath)
         Set-Location $rootFolder

codecov.yml

@@ -0,0 +1,3 @@
+codecov:
+  branch: dev
+  require_ci_to_pass: yes

common.test.props

@@ -7,4 +7,12 @@
     <GenerateAssemblyCompanyAttribute>false</GenerateAssemblyCompanyAttribute>
     <GenerateAssemblyProductAttribute>false</GenerateAssemblyProductAttribute>
   </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="3.1.0">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
+    </PackageReference>
+  </ItemGroup>
+
 </Project>