Windows: Dockerfile for TP5

Signed-off-by: John Howard <jhoward@microsoft.com>

Dockerfile.windows

@@ -19,21 +19,15 @@
 # Important notes:
 # ---------------
 #
-# 'Start-Sleep' is a deliberate workaround for a current problem on containers in Windows 
-# Server 2016. It ensures that the network is up and available for when the command is
-# network related. This bug is being tracked internally at Microsoft and exists in TP4.
-# Generally sleep 1 or 2 is probably enough, but making it 5 to make the build file
-# as bullet proof as possible. This isn't a big deal as this only runs the first time.
-#
-# The cygwin posix utilities from GIT aren't usable interactively as at January 2016. This
+# The posix utilities from GIT aren't usable interactively as at January 2016. This
 # is because they require a console window which isn't present in a container in Windows.
 # See the example at the top of this file. Do NOT use -it in that docker run!!! 
 #
-# Don't try to use a volume for passing the source through. The cygwin posix utilities will
+# Don't try to use a volume for passing the source through. The posix utilities will
 # balk at reparse points. Again, see the example at the top of this file on how use a volume
 # to get the built binary out of the container.
 #
-# The steps are minimised dramatically to improve performance (TP4 is slow on commit)
+# The steps are minimised dramatically to improve performance
 
 FROM windowsservercore
 
@@ -54,7 +48,6 @@ RUN \
  setx GOROOT "c:\go" && \
  powershell -command \
   $ErrorActionPreference = 'Stop'; \
-  Start-Sleep -Seconds 5; \
   Function Download-File([string] $source, [string] $target) { \
    $wc = New-Object net.webclient; $wc.Downloadfile($source, $target) \
   } \