Allow using env var to manage snapshot creation and update

[mathieutu]

fix #125

[freekmurze]

Looks good! Could you also mention these new env vars in the readme?

[mathieutu]

I've also added a mention to parallel testing to highlight it, in case of some devs are looking for the solution of their problems about that.

[mfn]

Random thought: would it make sense to promote using the env vars as being the preferred way and adjust the code checks and language used in the README?

I figure it certainly is more compatible and maybe the thought experiment for deprecating the -d --… approach could be done?

[freekmurze]

I figure it certainly is more compatible and maybe the thought experiment for deprecating the -d --… approach could be done?

I kinda like the -d -- approach to quickly rewrite snapshots when a failing tests is fixed.

[freekmurze]

It seems like tests are failing, could you take a look at that?

After the tests pass, I'll wait on a final stamp of approval by @sebastiandedeyne before merging and tagging this.

[mathieutu]

Actually suggestions are cools but no syntax checks or autocomplete! A semi is missing 😅

[sebastiandedeyne]

[freekmurze]

Thank you!

[mathieutu]

Always my pleasure!