Add `check()` API to retrieve the status of the system

[palazzem]

Overview

Closes #36

Adds a new public method to ElmoClient to make calls to multiple pages and endpoints to retrieve the global status of the system. It retrieves:

• Armed/Disarmed areas: https://connect.elmospa.com/api/areas | POST | sessionId
• Inputs status: https://connect.elmospa.com/api/inputs | POST | sessionId
• Area names: https://connect.elmospa.com/vendor/Areas | GET | only cookies
• Entries names: https://connect.elmospa.com/vendor/Inputs | GET | only cookies

Calling the method returns a Python dict with the following data:

{
  "areas_armed": [{"id": 0, "name": "Entryway"}, ...],
  "areas_disarmed": [{"id": 1, "name": "Kitchen"}, ...],
  "inputs_alerted": [{"id": 0, "name": "Door"}, ...],
  "inputs_wait": [{"id": 1, "name": "Window"}, ...],
}

# Check if any system input is in alerted state (so it will be excluded when the Alarm is ON)
assert len(status["inputs_alerted"]) == 0

# The Alarm is OFF
assert len(status["areas_armed"]) == 0

# The Alarm is ON
assert len(status["areas_armed"]) > 0