Fix Appveyor CI issues (OpenAPITools#9731)

* sleep for 15 seconds after starting the server

* fix sleep

* set clone depth to 1

appveyor.yml

@@ -29,8 +29,9 @@ install:
   - cmd: java -version
   - cmd: gradle -v
   - cmd: dir/w
-  - git clone https://github.com/wing328/swagger-samples
+  - git clone https://github.com/wing328/swagger-samples --depth 1
   - ps: Start-Process -FilePath 'C:\maven\apache-maven-3.2.5\bin\mvn' -ArgumentList 'jetty:run' -WorkingDirectory "$env:appveyor_build_folder\swagger-samples\java\java-jersey-jaxrs-ci"
+  - ps: Start-Sleep -s 15
   - ps: $PSVersionTable.PSVersion
   - ps: Install-Module -Name Pester -Force -Scope CurrentUser
 build_script: