doc(Appveyor): 增加代码覆盖率分析条件

#Comment
comment 仅GitHub Master分支进行代码覆盖率分析

appveyor.test.ps1

@@ -36,9 +36,14 @@ if ("$($env:APPVEYOR_REPO_BRANCH)" -eq "master")
 
     cd $($env:appveyor_build_folder)
 
+    if ("$($env:APPVEYOR_REPO_PROVIDER)" -eq "gitHub") {
         echo "" "Install coveralls.net tools"
         dotnet tool install coveralls.net --version 1.0.0 --tool-path "./tools"
 
         dotnet test UnitTest --no-restore /p:CollectCoverage=true /p:CoverletOutputFormat=opencover /p:Include="[Bootstrap*]*" /p:ExcludeByFile="../Bootstrap.Admin/Program.cs%2c../Bootstrap.Admin/Startup.cs%2c../Bootstrap.Admin/HttpHeaderOperation.cs" /p:CoverletOutput=../
         cmd.exe /c ".\tools\csmacnz.Coveralls.exe --opencover -i coverage.opencover.xml --useRelativePaths"
     }
+    else {
+        dotnet test UnitTest --no-restore
+    }
+}