Boca

- Custom commands:
- It is not mendatory anymore to declare a `click.Group` in the custom commands file. All `click.Command` objects declared in the file are mounted onto `boca`. This includes commands declared with `click.command()`, groups declared with `click.group()` and any other instance of a subclass of `click.Command`.
- **BREAKING**: The environment variable changed from `BOCA_CUSTOM_COMMANDS_FILE` to `BOCA_CUSTOM_COMMANDS`.

api.route("/")
view(methods=["post"])
async def foo(req, res):
pass


- Removed dependency on `async_generator`.