Django-flash-rest

* Documented the whole project in the `README.md` file.
* Fixed bug that raised `ValueError` instead of `SerializationError` during serialization.
* Made `ValidationError` available from `django_rest.deserializers`.
* Improved `setup.py` and updated project's version.
* Added MIT license file to the project (`LICENSE.md`).
* Added `setup.cfg` file.

* Renamed `PerforatedDeserializer` into `AllPassDeserializer`.
* Refactored class-based decorated view for better performances.
* Fixed CSRF token bug for writing HTTP methods.
* Fixed Permission evaluation (made dynamic).

Main changes:
* Implementing the first `Deserializer`class
* Assuring support for all python's versions (2.7+, 3+), and django's versions (1.11+).
* Type hinting to improve code's readability.

Core `api_view` changes:
* Supporting `deserializer_class` parameter.
* Supporting deserializer class mapping (custom deserializers for each http method).
* Adding `allow_forms` parameter to accept forms data or raise error.
* Supporting for `api_view` syntax (only `api_view()` was supported before)
* Checking view's type to make sure it's either a function or a `django.views.View` class
* Normalizing requests payload between content_types, so that the output's always in the same format.
* Extracting query params and passing custom parameters for the view (query params, payload, url params, etc.).
* Decorating only class view's relevant methods (http methods) instead of all methods.
* Moving helpers function into separate file.