fix(iterators): Rename iterator3.rs

Author: miller-time

exercises/standard_library_types/iterator3.rs renamed to exercises/standard_library_types/iterators3.rs

@@ -1,4 +1,4 @@
-// iterator3.rs
+// iterators3.rs
 // This is a bigger exercise than most of the others! You can do it!
 // Here is your mission, should you choose to accept it:
 // 1. Complete the divide function to get the first four tests to pass

info.toml

@@ -211,7 +211,7 @@ path = "exercises/standard_library_types/arc1.rs"
 mode = "compile"
 
 [[exercises]]
-path = "exercises/standard_library_types/iterator3.rs"
+path = "exercises/standard_library_types/iterators3.rs"
 mode = "test"
 
 [[exercises]]