enable colored print for REPL output

[aviatesk]

Won't be enabled for doctests (so I believe this should be safe).

[KristofferC]

Regarding doctests, how about producing colored output but stripping it before the comparison is made? I guess some people would not want that but it could be optional?

[aviatesk]

it could be optional?

So that people can do something like ?

julia> printstyled("red"; color=:red)
\e[31mred\e[39m

Honestly, I'm not super willing to support it. Maybe we can delay the support to the future until when someone finds it useful ?

[KristofferC]

No, I meant so that people can still do:

```jldoctest
julia> @test 1==1
Test Passed
```

but have Test Passed written in green (like in the REPL).

[aviatesk]

Ah, I see. But it seems it requires much refactors in order to replace the contents of generated document with the actual outputs of doctests.

[KristofferC]

It was probably bad form of me to comment on this PR. It wasn't really meant as anything that should be done here, it was just a related thought I hade when I read the PR description. I should just open a separate issue.

[fredrikekre]

Do you have an example of what this enables?

[aviatesk]

It was probably bad form of me to comment on this PR. It wasn't really meant as anything that should be done here, it was just a related thought I hade when I read the PR description. I should just open a separate issue.

I see. Thanks for the clarification :)

Do you have an example of what this enables?

An object may implement its own show method that may use color when enabled.
Probably the easiest repro would be something like:

```@repl; ansicolor=true
struct Foo end
Base.show(io::IO, ::Foo) = printstyled(io, "Foo"; color = :blue)

Foo()
```

[aviatesk]

@KristofferC so can this get merged (and maybe can we tag a patch release) ?

[fredrikekre]

Can you add a note in the changelog?

[aviatesk]

Sure. Added.