Fix typo

README.md

@@ -20,7 +20,7 @@ Performance
 ![Disk benchmark result](https://raw.github.com/ibireme/YYCache/master/Benchmark/Result_disk.png
 )
 
-You may [download](http://www.sqlite.org/download.html) and compile the lastest version of sqlite and ignore the libsqlite3.dylib in iOS system to get higher performance.
+You may [download](http://www.sqlite.org/download.html) and compile the latest version of sqlite and ignore the libsqlite3.dylib in iOS system to get higher performance.
 
 See `Benchmark/CacheBenchmark.xcodeproj` for more benchmark case.
 

YYCache/YYDiskCache.h

@@ -23,7 +23,7 @@
  * It can automatically decide the storage type (sqlite/file) for each object to get
       better performance.
  
- You may compile the lastest version of sqlite and ignore the libsqlite3.dylib in
+ You may compile the latest version of sqlite and ignore the libsqlite3.dylib in
  iOS system to get 2x~4x speed up.
  */
 @interface YYDiskCache : NSObject

YYCache/YYKVStorage.h

@@ -63,7 +63,7 @@ typedef NS_ENUM(NSUInteger, YYKVStorageType) {
  After initialized, a directory is created based on the `path` to hold key-value data.
  Once initialized you should not read or write this directory without the instance.
  
- You may compile the lastest version of sqlite and ignore the libsqlite3.dylib in
+ You may compile the latest version of sqlite and ignore the libsqlite3.dylib in
  iOS system to get 2x~4x speed up.
  
  @warning The instance of this class is *NOT* thread safe, you need to make sure