[Minor] Upgrade JUnit to 4.13

diff --git a/pom.xml b/pom.xml
index e49054f..98e5869 100644
--- a/pom.xml
+++ b/pom.xml
@@ -128,7 +128,7 @@
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
-      <version>4.11</version>
+      <version>4.13</version>
       <scope>test</scope>
     </dependency>
     <dependency>