v0.4.0

This release:

1. Adds support to download created calls data for a session, in the Messages tab
2. Rewrites the core functionality to be more modular
   • a Session object handles data flows for each user, in the Messages and Home tab
   • a View object handles changes to the interactive views, in the Messages and Home tab

Full Changelog: v0.3.0...v0.4.0