chore: bump compiler version and clippy fixes (#105)

Signed-off-by: Alex Chi Z <iskyzh@gmail.com>

mini-lsm-starter/src/lsm_iterator.rs

@@ -59,7 +59,10 @@ impl<I: StorageIterator> FusedIterator<I> {
 }
 
 impl<I: StorageIterator> StorageIterator for FusedIterator<I> {
-    type KeyType<'a> = I::KeyType<'a> where Self: 'a;
+    type KeyType<'a>
+        = I::KeyType<'a>
+    where
+        Self: 'a;
 
     fn is_valid(&self) -> bool {
         unimplemented!()

mini-lsm-starter/src/mvcc/txn.rs

@@ -104,7 +104,10 @@ impl TxnIterator {
 }
 
 impl StorageIterator for TxnIterator {
-    type KeyType<'a> = &'a [u8] where Self: 'a;
+    type KeyType<'a>
+        = &'a [u8]
+    where
+        Self: 'a;
 
     fn value(&self) -> &[u8] {
         self.iter.value()