consider using cf for colored printing

[Licenser]

In my crusade of killing all duplicated code for color printing on the console I'd wanted to offer the suggestion of using http://github.com/project-fifo/cf this. It includes a io:format like syntax for terminal colors along with termcap based detection of weather colors should be used or not.

[paulo-ferraz-oliveira]

@elbrujohalcon, this would add a dependency, but apart from that do we have so much coloured text that would warrant such a change?

[elbrujohalcon]

I'm not sure about using it in this project, but we should consider using it on inaka/elvis and maybe project-fifo/rebar3_lint

[paulo-ferraz-oliveira]

👍, I'll let you decide to keep this open or not. Maybe we'll reach the point where elvis_core doesn't actually output anything but simply creates the "outputables".

[elbrujohalcon]

Is it outputting something right now? Where is that outputting happening?

[elbrujohalcon]

Oh, I see.

[elbrujohalcon]

So, the idea is to replace those mustchoed colors (like {{red-bold}}) by whatever cf uses for that. I think it's a good idea, but I also think that this project should not be printing anything.