feat: completed solutions

exercises/12_options/options1.rs

@@ -4,6 +4,11 @@
 // `hour_of_day` is higher than 23.
 fn maybe_ice_cream(hour_of_day: u16) -> Option<u16> {
     // TODO: Complete the function body.
+    match hour_of_day {
+        0..22 => Some(5),
+        22..=23 => Some(0),
+        _ => None,
+    }
 }
 
 fn main() {
@@ -18,7 +23,7 @@ mod tests {
     fn raw_value() {
         // TODO: Fix this test. How do you get the value contained in the
         // Option?
-        let ice_creams = maybe_ice_cream(12);
+        let ice_creams = maybe_ice_cream(12).unwrap();
 
         assert_eq!(ice_creams, 5); // Don't change this line.
     }