sort-keys not working with spread props

[csantos1113]

Tell us about your environment

• ESLint Version: 5.3.0
• Node Version: 9.10.1
• npm Version: 5.6.0

What parser (default, Babel-ESLint, etc.) are you using?
None
Please show your full configuration:

{
    "parserOptions": {
        "ecmaVersion": 9,
        "sourceType": "script",
        "ecmaFeatures": {}
    },
    "rules": {
        "sort-keys": 2
    },
    "env": {
        "browser": true
    }
}

What did you do? Please include the actual source code causing the issue, as well as the command that you used to run ESLint.

const a = {
  a: 'a',
  x: 'x',
  b: 'b'
};

const b = {
  ...a,
  t: 't',
  d: 'd'
};

Fully replicable in ESLint Demo

What did you expect to happen?
I'm expecting to see errors in lines:
b: 'b' and d: 'd'

What actually happened? Please include the actual, raw output from ESLint.
I'm not getting the error in line d: 'd'

[ghost]

@keepitrio and I are looking forward to working on this!

[infctr]

yeah, that kinda renders this rule useless

[eslint-deprecated]

Unfortunately, it looks like there wasn't enough interest from the team
or community to implement this change. While we wish we'd be able to
accommodate everyone's requests, we do need to prioritize. We've found
that issues failing to reach accepted status after 21 days tend to
never be accepted, and as such, we close those issues.
This doesn't mean the idea isn't interesting or useful, just that it's
not something the team can commit to.

Thanks for contributing to ESLint and we appreciate your understanding.