inherit buildOptions in extended factories

[sienic]

Probably the solution to: simonexmachina/factory-girl#134

• Given a parentFactory defined with buildOptions with its respective callbacks.
• Given a childFactory that extends that parentFactory.
• Whenever a models is built out of the aforementioned childFactory,
• the callbacks defined in the parentFactory are not being called.

const parentFactory = FactoryGirl.define('parent', Model, initializer, buildOptions);
const childFactory = FactoryGirl.extend('parent', 'child');

// whenever we build a childFactory, i.e.
await FactoryGirl.build('child');
// the `afterBuild`, and `afterCreate` callbacks set in parentFactory are not being called

This PR aims to solve this.
(the linter run at the pre commit hook added some style changes).

[ratson]

@sienic Thank you for the PR, close #8

[sienic]

@ratson thank you for the release! 🙌