Add automated code coverage to appveyor

appveyor.yml

@@ -22,7 +22,22 @@ build:
   verbosity: minimal
 test_script:
 - cmd: >-
-    %xunit20%\xunit.console.x86 "bin\Release\StreamJsonRpc.Tests\StreamJsonRpc.Tests.dll" -noshadow -html bin\release\testresults.html -xml bin\release\testresults.xml -appveyor -notrait "TestCategory=FailsInCloudTest" -nologo
+    "%userprofile%\.nuget\packages\OpenCover\4.6.519\tools\OpenCover.Console.exe" 
+    -register:user
+    -target:"%xunit20%\xunit.console.x86.exe"
+    -targetargs:"bin\Release\StreamJsonRpc.Tests\StreamJsonRpc.Tests.dll -noshadow -html bin\release\testresults.html -xml bin\release\testresults.xml -appveyor -notrait TestCategory=FailsInCloudTest -nologo"
+    -returntargetcode
+    -excludebyattribute:*.ExcludeFromCodeCoverage*
+    -excludebyfile:*\*Designer.cs
+    -filter:"+[StreamJsonRpc]*"
+    -hideskipped:All
+    -output:bin\Release\code_coverage.xml
+
+    SET PATH=C:\Python34;C:\Python34\Scripts;%PATH%
+
+    pip install codecov
+
+    codecov -f "bin\Release\code_coverage.xml"
 artifacts:
 - path: bin\**\*.nupkg
   name: NuGet Package

src/StreamJsonRpc.Tests/project.json

@@ -1,5 +1,6 @@
 {
   "dependencies": {
+    "OpenCover": "4.6.519",
     "MicroBuild.NonShipping": "2.0.34",
     "Nerdbank.FullDuplexStream": "1.0.1",
     "System.Collections.Immutable": "1.2.0",