Fix clippy warnings (#2065)

Author: senekor

Diff for: exercises/practice/all-your-base/.meta/example.rs

@@ -36,7 +36,7 @@ pub enum Error {
 /// Notes:
 ///  * The empty slice ( "[]" ) is equal to the number 0.
 ///  * Never output leading 0 digits. However, your function must be able to
-///     process input with leading 0 digits.
+///    process input with leading 0 digits.
 ///
 pub fn convert<P: AsRef<[Digit]>>(
     digits: P,

Diff for: exercises/practice/dominoes/.meta/example.rs

@@ -1,5 +1,3 @@
-use std::iter;
-
 pub type Domino = (u8, u8);
 
 /// A table keeping track of available dominoes.
@@ -14,7 +12,7 @@ struct AvailabilityTable {
 impl AvailabilityTable {
     fn new() -> AvailabilityTable {
         AvailabilityTable {
-            m: iter::repeat(0).take(6 * 6).collect(),
+            m: std::iter::repeat_n(0, 6 * 6).collect(),
         }
     }