Epicstore-api

* Fixed a bug where `fetch_store_games` does not return the game's price even when `with_price` argument is True.

* Move author and version into setup.py ([8](https://github.com/SD4RK/epicstore_api/pull/8))

* Slight changes in docstrings for more readability.
* Updated get_offers_data and offers query.

Added new functions to interact with the store.

* get_addons_by_namespace - To fetch games' addons.

* fetch_media & fetch_multiple_media_files - To fetch games' media files.

* get_product_reviews - To fetch games' reviews (if exists).

- Added a new function "get_free_games".
- Fixed an exception in "get_store" method.