finish skeleton for serializability check

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

mini-lsm/src/lsm_storage.rs

@@ -78,6 +78,7 @@ pub struct LsmStorageOptions {
     pub num_memtable_limit: usize,
     pub compaction_options: CompactionOptions,
     pub enable_wal: bool,
+    pub serializable: bool,
 }
 
 impl LsmStorageOptions {
@@ -88,6 +89,7 @@ impl LsmStorageOptions {
             compaction_options: CompactionOptions::NoCompaction,
             enable_wal: false,
             num_memtable_limit: 50,
+            serializable: false,
         }
     }
 
@@ -98,6 +100,7 @@ impl LsmStorageOptions {
             compaction_options: CompactionOptions::NoCompaction,
             enable_wal: false,
             num_memtable_limit: 2,
+            serializable: false,
         }
     }
 
@@ -108,6 +111,7 @@ impl LsmStorageOptions {
             compaction_options,
             enable_wal: false,
             num_memtable_limit: 2,
+            serializable: false,
         }
     }
 }