Allow spaces inside curly braces of hash literals

[triskweline]

I would like makandra-rubocop to allow spaces inside hash literals, e.g. hash = { foo: 'bar' }. This is currently enforced to be hash = {foo: 'bar'}.

Some points:

• Allowing (even enforcing!) spaces is the Rubocop default
• The Rubocop community style guide says both styles are acceptable
• Hash literals correspond to JavaScript object literals, each of us spends half their day in JavaScript, and spaces inside literal braces is a convention for JS object literals.

The cop is SpaceInsideHashLiteralBraces.