feat(config): add envDir option

[GavinRay97]

Close #2113

Fork of #2123 with reviewer-requested changes, branched from latest master
CC @aleclarson

[Shinigami92]

question: Is this a breaking change? Do we need all to change our files from .env to env/.env after this feat gets merged?

[aleclarson]

It's not a breaking change. See here:

const envDir = config.envDir
  ? normalizePath(path.resolve(resolvedRoot, config.envDir))
  : resolvedRoot

[Shinigami92]

If I see correctly, we now have no test/playground for the default case anymore
You may consider to copy the env playground and test it specifically

[Shinigami92]

#3407 (review)

[aleclarson]

@Shinigami92 I reverted the change to playground/env. I think we can merge this without its own playground, since the feature is simple enough that a regression is unlikely.

[Shinigami92]

@Shinigami92 I reverted the change to playground/env. I think we can merge this without its own playground, since the feature is simple enough that a regression is unlikely.

Okay, just spend me a 🍺 somedays if there is a regression in the future 😃

[aleclarson]

@Shinigami92 Deal! Just need your review approval and LGTM :)