Upgrade junit from 4.12 to 4.13

diff --git a/pom.xml b/pom.xml
index bdd9a9b..3b36466 100644
--- a/pom.xml
+++ b/pom.xml
@@ -125,7 +125,7 @@
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
-      <version>4.12</version>
+      <version>4.13</version>
       <scope>test</scope>
     </dependency>
   </dependencies>