SLING-3813 - Pax-Exam tests fail when executed under Java 8

Downgrade pax-exam version to 3.5.0 to ensure that tests can be executed
with Java 6.

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1615343 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index ba77369..7117c69 100644
--- a/pom.xml
+++ b/pom.xml
@@ -49,7 +49,7 @@
         <bundle.file.name>
             ${bundle.build.name}/${project.build.finalName}.jar
         </bundle.file.name>
-        <pax-exam.version>4.1.0</pax-exam.version>
+        <pax-exam.version>3.5.0</pax-exam.version>
         <pax-link.version>2.1.0</pax-link.version>
     </properties>