use proper hydro license; add fluctuation

src/model/mod.rs

@@ -1,6 +1,7 @@
 use chrono::NaiveDate;
 use serde::Serialize;
 use sqlx::SqlitePool;
+use waterlevel::WaterlevelDay;
 
 use self::{
     event::{Event, EventWithUserAndTriptype},
@@ -38,7 +39,7 @@ pub struct Day {
     events: Vec<EventWithUserAndTriptype>,
     trips: Vec<TripWithUserAndType>,
     is_pinned: bool,
-    max_waterlevel: Option<i64>,
+    max_waterlevel: Option<WaterlevelDay>,
     weather: Option<Weather>,
 }