lower minimum required version of lang3 to 3.6
diff --git a/pom.xml b/pom.xml
index d9ecd3b..a15b276 100644
--- a/pom.xml
+++ b/pom.xml
@@ -62,7 +62,7 @@
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-lang3</artifactId>
-            <version>3.9</version>
+            <version>3.6</version>
             <scope>provided</scope>
         </dependency>