Recreate dynamo db instance on .local()

[renanvalentin]

The current solution requires .local() to be called first in order to
use dynamo db locally.

Recreating dynamo db instance when calling .local() solves issues like
script import order.

Example:

// evil-cat.js
import dynamoose from 'dynamoose';

export const EvilCat = dynamoose.model('Cat', { id: Number, name: String });

// evil-cat.test.js
import dynamoose from 'dynamoose';
import { EvilCat } from 'db/evil-cat';

beforeAll(() => {
  dynamoose.local(); // won't work because dynamoose was already initialized inside of evil-cat.js 
});

[fishcharlie]

@renanvalentin Looks like this could be valuable. But the tests are failing due to linter errors. Can you run the tests locally (npm test) and fix those? 🙂

[coveralls]

Coverage increased (+0.02%) to 82.511% when pulling 8f0d130 on renanvalentin:fix-local-db into 310da5c on automategreen:master.

[renanvalentin]

@fishcharlie Fixed 🗡

[fishcharlie]

LGTM

[fishcharlie]

We'll get this merged in for version 0.9. Thanks so much!