docs(developers.md): update node version as specified in package.json

[skryvets]

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

Docs update

What is the current behavior? (You can also link to an open issue here)

DEVELOPERS.MD contains different node version from package.json. Yarn install works with 8.9.1+ only and doesn't work with 6.x as specified in docs.

What is the new behavior (if this is a feature change)?

Docs are updated in accordance with package.json.

Does this PR introduce a breaking change?

Not.

Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Fix/Feature: Docs have been added/updated
• Fix/Feature: Tests have been added; existing tests pass

Other information:
Sorry, this might be a very small and not significant fix, but I guess still requires some attention.

[Narretz]

Hi, thanks for the PR. This is not 100% correct, though - the version we support is ^8.9.1, which means any 8.x.x version is supported. Could you adjust the PR accordingly?

[skryvets]

Hi, @Narretz. Sorry, I misunderstood.

Could you adjust the PR accordingly?

Sure. I just pushed my changes.
Thank you a lot for explaining why is that :-)

[Narretz]

@sergeome Thanks, merged. Do you mean why 8.x is correct, but 8.9.1 is not? It's because the ^ means a range of acceptable releases, starting with 8.9.1, but also for example 8.10 if that were ever released ... (see https://stackoverflow.com/a/22345808/787333). Which makes a realize, 8.x isn't exactly correct, because the minimum is 8.9.1. But that's okay for now.

[skryvets]

That was my initial point,

I cloned the repo, looked at the docs and it didn't work for me. I noticed that in package.json there is node ^8.9.1:

...
"engines": {
    "node": "^8.9.1", <- This guy
    "yarn": ">=1.3.2",
    "grunt": "^1.2.0"
  },
...

Whereas in the docs it was 6.x.

I agree that 8.x is still more correct than 6.x :-)

Anyways, will adjust next time, when would create another PR if this item will have a place.
Thank you, @Narretz!