v0.0.3: Simplify asyncio code and fix warnings

Based on guidance from Python concurrency with Asyncio by Matthew Fowler, this release simplifies the asyncio code, and fixes some warning:

• It makes sure coroutines that were not properly awaited are now awaited.
• It uses asyncio.create_task() and asyncio.run() instead of manually creating and keeping track of the event loop.

Add Port object

This is a very small change, adding a Port object (subclassing asyncio.Queue), so that the user don't need to import the asyncio library at all, thus making user code cleaner.

First working version

This is the first barely working version. See the examples folder for an example that uses the library.