add additional fitbit endpoints for SPO2 and skin temp

[lila]

new webapis were added last year:

• https://dev.fitbit.com/build/reference/web-api/spo2/
• https://dev.fitbit.com/build/reference/web-api/temperature/

[lila]

added SPO2 (daily summary) and skintemp (daily). the code is available in the branch for now, i'll merge it in when i can add the spo2 intraday.

The bigquery schema for the SPO2 (daily summary) looks like this:

and the skinTemp looks like this:

k

[lila]

SPO2 intraday requires specific approval for the application. see https://dev.fitbit.com/build/reference/web-api/intraday/