Remove TODO from 2 solutions

solutions/06_move_semantics/move_semantics4.rs

@@ -4,8 +4,6 @@ fn main() {
 
 #[cfg(test)]
 mod tests {
-    // TODO: Fix the compiler errors only by reordering the lines in the test.
-    // Don't add, change or remove any line.
     #[test]
     fn move_semantics4() {
         let mut x = Vec::new();

solutions/19_smart_pointers/rc1.rs

@@ -63,12 +63,10 @@ mod tests {
         println!("reference count = {}", Rc::strong_count(&sun)); // 7 references
         saturn.details();
 
-        // TODO
         let uranus = Planet::Uranus(Rc::clone(&sun));
         println!("reference count = {}", Rc::strong_count(&sun)); // 8 references
         uranus.details();
 
-        // TODO
         let neptune = Planet::Neptune(Rc::clone(&sun));
         println!("reference count = {}", Rc::strong_count(&sun)); // 9 references
         neptune.details();