Update mfi.py to include mFi-DS Door Sensors

[Bakkoda]

Add ability to read door sensor states from the mPort.

Description:

Assuming your mFi setup is already working with Home Assistant this will also allow the Door Sensors to be polled from the mPort. A quick sensor template will show them as doors.

Related issue (if applicable): fixes #

Pull request in home-assistant.github.io with documentation (if applicable): home-assistant/home-assistant.github.io#<home-assistant.github.io PR number goes here>

Example entry for configuration.yaml (if applicable):

binary_sensor:
  - platform: template
    sensors: 
        front_door:
            friendly_name: "Your Door Name"
            device_class: door
            value_template: '{{ states("sensor.door") == "0.0" }}'

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in home-assistant.github.io

If the code communicates with devices, web services, or third-party tools:

• New dependencies have been added to the REQUIREMENTS variable (example).
• New dependencies are only imported inside functions that use them (example).
• New dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.
• New files were added to .coveragerc.

If the code does not interact with devices:

• Tests have been added to verify that the new code works.

[fabaff]

Thanks 🐦