v0.40.0a13

Highlights of changes in this version

• Full rewrite from threaded into async (which fits better to Home Assistant)
• Local caching of energy data to speedup loading the integration after a restart and minimize network congestion issues
• Improved message handling by properly utilizing the status response from USB-stick
• Added tests to ensure working of library. (no full coverage yet)

Full Changelog: v0.31.3...v0.40.0a13