Bump junit from 4.13 to 4.13.1 (#41)

diff --git a/pom.xml b/pom.xml
index 5a0c552..067ea8e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -144,7 +144,7 @@
             <dependency>
                 <groupId>junit</groupId>
                 <artifactId>junit</artifactId>
-                <version>4.13</version>
+                <version>4.13.1</version>
                 <scope>test</scope>
             </dependency>
         </dependencies>