included check for string literal 'error'

[imjordanxd]

What is the purpose of this pull request?
Now shows an error if callback has "error" as the first param.

• Documentation update
• Bug fix
• New rule
• Changes an existing rule
• Add autofixing to a rule
• Other, please explain:

What changes did you make? (Give an overview)
Original if statement only checked the first param name was "err". Now it also checks for "error"

[xjamundx]

Trying to think of any reason this might cause issues. Can you think of any? In general i think this makes sense. Might be a breaking change though.

[imjordanxd]

No, I can't think of any issues. Unsure how this might become a breaking change?

[xjamundx]

I'm fine with this goign out as a minor change, should we update the docs as well. I can probably do that later.

[jturel]

Hey! This change is breaking our linting. I ask that you pardon my ignorance since I don't consider myself a JS developer, and I say that because I don't understand the significance of this change with respect to checking for a parameter called 'error' in this rule.

I'm seeing this:

/home/vagrant/katello/webpack/scenes/Tasks/helpers.js
  14:32  error  Avoid callbacks. Prefer Async/Await  promise/prefer-await-to-callbacks

The function in question is here: https://github.com/Katello/katello/blob/a7a07cb664d2de2cb56889d63c1cfcb3d4d54d41/webpack/scenes/Tasks/helpers.js#L12-L18

Changing the param from error to anything else avoids firing this rule. I have no issue with changing the param name in our code but it does seem odd, so I am sharing this here in case the rule needs adjustment.

[xjamundx]

@jturel filed this issue to discuss #212