Fix for https://github.com/jwood803/xfsharp/pull/1

[sergey-tihon]

Messages to stderr stream can break the build

[forki]

I don't really understand. We do this everywhere in FAKE

[sergey-tihon]

Yep, when AppVeyor configured to run build.cmd using cmd (like here) everything should be OK.

build_script:
  - cmd: build.cmd

but if you (for some reason) run build.cmd using PowerShell

build_script:
  - ps: .\build.cmd

you could not write to stderr stream.

So, probable it not a reason to modify FAKE ...
Or would be better to release some kind of guides how to configure Travis-CI and AppVeyor to run FAKE scripts, and that is not a very good idea to use PowerShell ISE for running FAKE scripts or you need to redirect stderr stream.

// cc @jwood803

[jwood803]

I think the guide on how to configure the two to run the FAKE scripts would work well. If that works, I'll be glad to take a shot at it.