Merge two code coverage uploads to one

appveyor.yml

@@ -46,8 +46,7 @@ after_test:
     - .\csharp\packages\OpenCover.4.6.166\tools\OpenCover.Console.exe -register:user -target:.\csharp\packages\NUnit.Console.3.0.1\tools\nunit3-console.exe -register:user "-targetargs:"".\csharp\WorkerTest\bin\Debug\WorkerTest.dll"" "".\csharp\AdapterTest\bin\Debug\AdapterTest.dll"" " -filter:"+[CSharpWorker*|Microsoft.Spark.CSharp*]*" -excludebyattribute:*.ExcludeFromCodeCoverage* -hideskipped:All -output:.\SparkCLRCodeCoverage.xml
     - "SET PATH=C:\\Python34;C:\\Python34\\Scripts;%PATH%"
     - pip install codecov
-    - codecov -f "NativeCodeCoverage.xml"
-    - codecov -f "SparkCLRCodeCoverage.xml"
+    - codecov -f "NativeCodeCoverage.xml" "SparkCLRCodeCoverage.xml"
     - cmd: cd .\build\localmode
     - cmd: if not defined ProjectVersion (.\Runsamples.cmd --validate)
     - cmd: cd ..\..