Publish test logs to AppVeyor Artifacts (#1411)

.appveyor.yml

@@ -10,6 +10,11 @@ branches:
     - /^rel\/.*/
 build_script:
   - ps: .\run.ps1 default-build
+  - ps: "7z a testlogs.zip testlogs"
+artifacts:
+  - path: testlogs.zip
+    name: TestLogs
+    type: Zip
 install:
   - ps: Install-Product node 8
 clone_depth: 1
@@ -17,6 +22,7 @@ environment:
   global:
     DOTNET_SKIP_FIRST_TIME_EXPERIENCE: true
     DOTNET_CLI_TELEMETRY_OPTOUT: 1
+    ASPNETCORE_TEST_LOG_DIR: "$(APPVEYOR_BUILD_FOLDER)\\testlogs"
 test: off
 deploy: off
 os: Visual Studio 2017