feat: 优化 gradle 编译
feat: 将 org.apache.log4j 替换为 slf4j
feat: 优化代码去掉warning
diff --git a/gradle.properties b/gradle.properties
index b59ebef..f72e65c 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,4 +1,4 @@
 springbootVersion = 2.1.3.RELEASE
-kotlinVersion = 1.2.41
+kotlinVersion = 1.3.31
 payapiVersion = 1.0
 jdkVersion = 1.8
\ No newline at end of file