Stack upgrade --git prints escape codes to the terminal

[ndmitchell]

Using stack 1.5.1 on Windows, doing a stack upgrade --git I see:

That's not a great user experience because of the escape codes. Using the ansi-terminal package you would get nicer looking output in a cross-compatible way.

[ndmitchell]

Perhaps what is most sad is that ANSI escape codes are all "display as normal" (0m), so if omitted entirely would have no effect on any system and be simpler.