SLING-8936 Improve test coverage for path-mounted servlets

* Use Testing PaxExam 3.1.0
diff --git a/pom.xml b/pom.xml
index a447c47..c91c48f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -270,7 +270,7 @@
         <dependency>
             <groupId>org.apache.sling</groupId>
             <artifactId>org.apache.sling.testing.paxexam</artifactId>
-            <version>3.0.0</version>
+            <version>3.1.0</version>
             <scope>test</scope>
         </dependency>
         <dependency>