Run cargo clippy on whole project (#322)

* Run cargo clippy on plume-common

Run clippy on plume-common and adjuste code accordingly

* Run cargo clippy on plume-model

Run clippy on plume-model and adjuste code accordingly

* Reduce need for allocation in plume-common

* Reduce need for allocation in plume-model

add a quick compilation failure if no database backend is enabled

* Run cargo clippy on plume-cli

* Run cargo clippy on plume

src/routes/notifications.rs

@@ -24,6 +24,6 @@ fn notifications(conn: DbConn, user: User) -> Template {
 fn notifications_auth() -> Flash<Redirect>{
     utils::requires_login(
         "You need to be logged in order to see your notifications",
-        uri!(notifications).into()
+        uri!(notifications)
     )
 }