Add code to download history

[jhoult]

The website lets you download the history for the past week at /xxl_history/$thermosat_id/daily_history.json or the histor for the last month at /xxl_history/$thermosat_id/daily_history.json

It also supports a csv:
https://www.mynexia.com/xxl_history/$thermostat_id/monthly_history.csv
https://www.mynexia.com/xxl_history/$thermostat_id/daily_history.csv

[jhoult]

when you try to use nexia.home._get_url it causes a redirect loop. Nexia responds with a 302 redirect to the CDR you ask for constantly, which causes the library to log back in, then try again, which then gives you another 302, and does it over and over.