* Add development requirements.txt

* Update roadmap.jpg, README.md

* Improve background_tasks.py, generate_ws_connection_id()

* Add Image Type for serializer + Add size to File Type

* Fix a bug on loading urls on single-file structure

* Improve the way of loading configs in single-file structure

* bpython removed from being the default python shell

* Improve load_middlewares() error handling

* Print configs on the `run`