update to latest JUnit 5.8.1 (#325)

Author: ddsharpe

pom.xml

@@ -71,7 +71,7 @@
             <dependency>
                 <groupId>org.junit.jupiter</groupId>
                 <artifactId>junit-jupiter-engine</artifactId>
-                <version>5.6.0</version>
+                <version>5.8.1</version>
             </dependency>
             <dependency>
                 <groupId>com.google.guava</groupId>