update Swift version in README

biuer · biuer · commit 89e600f2b3ca · 2018-12-27T10:45:30.000+08:00
diff --git a/README.md b/README.md
@@ -10,7 +10,7 @@
 # 环境要求
 
 - iOS 8.0+
-- Swift 4.1
+- Swift 4.2
 
 # 安装
 
