Override formatter colors from envvars

[blacksails]

This allows a user to set environment variables
GINKGO_CLI_COLOR_<color> with asci code overrides. This helps a lot when the colorscheme that you are using doesn't play well with the colors from the 256 color scheme which currently is hard coded.

Example GINKGO_CLI_COLOR_RED=$'\x1b[31m' ginkgo will use the red from the 8bit colors configured in the terminal.

[blacksails]

I dont nessesarily expect this to get merged as-is, but I would love an option to be able to change the colors of the terminal output. I am open to any input with regards to how this could be done differently.

The formatter testsuite currently fails if environment variables are overridden. I guess the before each needs to unset the environment variables to ensure that the tests give the expected results. Fixed in 7b768db

[onsi]

hey there - longer term my plan is to add support for some sort of .ginkgoconfig file or something that would be a natural place for something like this. For now environment variables seem fine but I'd like to reserve the right to deprecate them at some point and transition to a config file based approached.

Happy to pull this in once CI goes green, with those caveats.

[blacksails]

@onsi Yea this could also be better implemented.

The following values would be nice to map in order to make configuration way easier.

For the standard 16 colors
red => \x1b[31m
1 => \x1b[31m
bright-red => \x1b[31;1m
8 => \x1b[31;1m

For extended 256 colors
16 => \x1b[38;5;16m

[onsi]

hey, i think that's fine - but perhaps i'm not following? are you planning on another PR to support those aliases?

[blacksails]

@onsi yea will do it today.