Reconsider capIsNew: false for new-cap

With `eslint-config-airbnb-base@8.0.0` the code
```js
class Example {}
module.exports = Example();
```
would result in the error:

example.js:2:18: A function with a name starting with an uppercase letter should only be used as a constructor. [Error/new-cap]

As a result of #1090, which set `capIsNew: false` for `new-cap`, this is no longer the case.

https://github.com/airbnb/javascript/issues/1089#issuecomment-249409624 which motivated the change only mentions adding `"capIsNewExceptions": ["Immutable.Map", "Immutable.Set", "Immutable.List"]`. Would it make sense to revert `capIsNew: false` (and perhaps adopt `"capIsNewExceptionPattern": "^Immutable.\\w"` as suggested in #1106) or was there another rationale for setting `capIsNew: false`?

Thanks,
Kevin

Start by reviewing the new-cap configuration change from #1090 and the rationale in the linked Airbnb issue, then reproduce the shown class and function-call example with eslint-config-airbnb-base@8.0.0. Compare reverting capIsNew with using capIsNewExceptions or capIsNewExceptionPattern, and consider the related proposal in #1106. Done means the intended behavior and configuration are agreed and covered by the project's relevant checks.

Written by the indexing model from the issue text.