Support for custom store class

[marden]

At the moment there is no way to specify custom store for Factory Muffin.

This PR adds support for storeClass config variable to specify a class to be used as a store.

Module config example:

modules:
  config:
    DataFactory:
      factories: tests/_support/factories
      storeClass: \common\tests\store\MyCustomStore

[DavertMik]

Thanks @marden !

1. What if the store requires some arguments on creation? This config doesn't cover this case. Could you mention explicitly in the documentation that the class will be created via constructor with no extra params. Or maybe instead of a class name ask for a factory method so it could create any kind of store.
2. Could you provide usage example in documentation? Documentation is inside the same file in docblocks.

[marden]

@DavertMik Thanks for the feedback.

• Renamed parameter to customStore
• It can be a simple class or a factory with create method
• Updated doc.

[marden]

@DavertMik Please review.

[marden]

@DavertMik Hello?

[DavertMik]

Thanks! Looks good to me!
Merging