Slack View now based on Python with Real Time Streaming.

[meltaxa]

For PHP users, Slack View PHP version is available on the php branch.

The new Python version has the following new features:

• Real Time Streaming. Leverages Flask-SocketIO.
• The Slack View app can stream multiple Slack channels on each Slack View web page.
• Themes. Choose a theme to persoksnalize Slack View. Create your own custom theme.
• Dockerized for quick deployment.

See the README for more.

Still work to be done to add more themes, render reactions, links and other attachments.