Envoy-reader

- Added support for firmware 7.x.x. This new firmware requires an Internet connection to retrieve a token from Enphase Enlighten servers, to be able to locally retrieve your Envoy statistics.
- Example usage to run `envoy_reader` from the command line for firmware <7.0 - (*Note: Has not changed in this release just given as a reference*)
- `python envoy_reader.py`
- Example usage to run `envoy_reader` from the command line for firmware >=7.0:
- To retrieve a token for a Commissioned Envoy from Enphase Enlighten:
- `python envoy_reader.py -u emailfred.com -p password -c True -i SiteID -s EnvoySerial`
- To retrieve a token for an Uncommissioned Envoy from Enphase Enlighten:
- `python envoy_reader.py -u emailfred.com -p password -c False`

- Updated Readme to include the known issue of envoy_reader not working with Envoys running firmware D7.x.x

- Use httpx API >= 0.20
- Define MIT license in setup.py

- Adds support to generate and use the password for the `installer` user account

- Added support for returning Battery data from the current /production.json page

- Add a flag to control retrieving invertor data PR 68