Git bash seems to be only way to successfully execute cf update-service on Windows 10

[pacphi]

In lab 4 there's a step where you are asked to update the configuration of the instance of the config server so that it references application configuration from a Git repository. There is no facility at moment to do this directly from Application Manager UI. So, one has to execute something like cf update-service config-server -c '{"git": { "uri": "https://github.com/pacphi/config-repo" } }'. We've not been able to see participants on Windows 10 laptops successfully execute the above cf command in cmd or powershell. What seems to work consistently, is when they launch a Git bash shell.

The scope of this effort is to troubleshoot and fix so that all three shells function equivalently when execute cf update-service ....