fixes #12 remove the json-overlay version to use light-4j version (#13)

Author: stevehu

pom.xml

@@ -66,7 +66,6 @@
         <java.version>1.8</java.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <version.light-4j>1.6.0</version.light-4j>
-        <version.json-overlay>1.6.0</version.json-overlay>
         <version.jackson>2.9.8</version.jackson>
         <version.javamail>1.6.1</version.javamail>
         <version.slf4j>1.7.25</version.slf4j>
@@ -96,7 +95,7 @@
         <dependency>
             <groupId>com.networknt</groupId>
             <artifactId>json-overlay</artifactId>
-            <version>${version.json-overlay}</version>
+            <version>${version.light-4j}</version>
         </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>