weather: forecast up to 10 days

This service needs api key. For now I put it straightly into the url
It will need to be replaced, like in perl with {{ENV_APIKEY}} , but not sure if python supports this. Gonna look at it deeply.

Signed-off-by: Adrian Matejov <a.matejov@centrum.sk>
@Adman `diff` is a bit disamgiuous. In here it probably refers to the date difference between today and the date we want to know the prediction of