Remove updating Docker, is already 1.13.1

Author: StefanScherer

appveyor.yml

@@ -8,17 +8,6 @@ environment:
     secure: 4gsl5WiqIztEWhL5fuhp9X0qT/mKg9fYzKYUUPf5WStIuNddv0fvIKGmvvyuFzzd
 install:
   - docker version
-  # the official way to update to Docker 1.13.1 CS
-  # - ps: Install-Package -Name docker -ProviderName DockerMsftProvider -Verbose -Update -Force
-  # - ps: Start-Service docker
-  # the faster way to update to Docker 1.13.1 CS
-  - ps: >-
-      $ProgressPreference = 'SilentlyContinue';
-      Invoke-WebRequest -Outfile $env:TEMP\docker-1.13.1.zip https://dockermsft.blob.core.windows.net/dockercontainer/docker-1-13-1.zip -UseBasicParsing;
-      Stop-Service docker;
-      Expand-Archive $env:TEMP\docker-1.13.1.zip -DestinationPath $env:ProgramFiles -Force;
-      Start-Service docker
-  - docker version
 
 build_script:
   - ps: .\build.ps1