Models: initialize lifecycle method.

[fahad19]

Like services and factories, a new initialize() lifecycle method has been added.

// ./models/MyModelName.js
import { createModel } from 'frint';

export default createModel({
  initialize(attributes = {}) {
    // `attributes` contains all constructor options
  }
});

[coveralls]

Coverage remained the same at 100.0% when pulling b839929 on models-initialize into 954d2da on master.