chore: Alter whitespace for consistency

* Add newline after "I AM DONE" in exercises for consistency
* Remove trailing whitespace from exercises

exercises/traits/traits1.rs

@@ -1,21 +1,21 @@
 // traits1.rs
 // Time to implement some traits!
-// 
+//
 // Your task is to implement the trait
 // `AppendBar' for the type `String'.
-// 
+//
 // The trait AppendBar has only one function,
 // which appends "Bar" to any object
 // implementing this trait.
 
 // I AM NOT DONE
+
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
 impl AppendBar for String {
     //Add your code here
-
 }
 
 fn main() {
@@ -40,5 +40,4 @@ mod tests {
             String::from("BarBar")
         );
     }
-
-}
+}

exercises/traits/traits2.rs

@@ -1,12 +1,12 @@
 // traits2.rs
-// 
+//
 // Your task is to implement the trait
 // `AppendBar' for a vector of strings.
-// 
+//
 // To implement this trait, consider for
 // a moment what it means to 'append "Bar"'
 // to a vector of strings.
-// 
+//
 // No boiler plate code this time,
 // you can do this!
 
@@ -31,5 +31,4 @@ mod tests {
         assert_eq!(foo.pop().unwrap(), String::from("Bar"));
         assert_eq!(foo.pop().unwrap(), String::from("Foo"));
     }
-
 }