1. write out avgTempPast24Hours function

2. write out maxTempPast24Hours function

3. create a button then when pressed will send a post request to 'https://myserver.com/averageTemps' with the current average temp.

4. show "loading..." text while request is being made

5. implement a FlatList that displays all temps and loads at most 10 more when you scroll to the bottom of the list