v3.0

With this new release we no longer maintain 'HDMI-CEC' branch due to it can be achieved using the new turn_on_action command

Changelog

• Added turn_on_action (#40)
• Don't try to set volume if it's not possible (#41)
• Wait for TV to power on before trying to change source (#42)
• Add function names to debug logging to help track flow (#43)
• Improve README